Pyrrolo[3,2-d]pyrimidin-4-one derivatives and their use in therapy

ABSTRACT

There are disclosed novel compounds of formula (I) 
     
       
         
         
             
             
         
       
     
     wherein R 1 , R 12 , L, X and Y are as defined in the specification, and pharmaceutically acceptable salts thereof; together with processes for their preparation, compositions containing them and their use in therapy. The compounds are inhibitors of the enzyme MPO and are thereby particularly useful in the treatment or prophylaxis of neuroinflammatory disorders, cardiovascular disorders and respiratory disorders.

FIELD OF THE INVENTION

The present invention relates to novel pyrrolo[3,2-d]pyrimidin-4-onederivatives, processes for their preparation, compositions containingthem and their use in therapy.

BACKGROUND OF THE INVENTION

Myeloperoxidase (MPO) is a heme-containing enzyme found predominantly inpolymorphonuclear leukocytes (PMNs). MPO is one member of a diverseprotein family of mammalian peroxidases that also includes eosinophilperoxidase, thyroid peroxidase, salivary peroxidase, lactoperoxidase,prostaglandin H synthase, and others. The mature enzyme is a dimer ofidentical halves. Each half molecule contains a covalently bound hemethat exhibits unusual spectral properties responsible for thecharacteristic green colour of MPO. Cleavage of the disulphide bridgelinking the two halves of MPO yields the hemi-enzyme that exhibitsspectral and catalytic properties indistinguishable from those of theintact enzyme. The enzyme uses hydrogen peroxide to oxidize chloride tohypochlorous acid. Other halides and pseudohalides (like thiocyanate)are also physiological substrates to MPO.

PMNs are of particular importance for combating infections. These cellscontain MPO, with well documented microbicidal action. PMNs actnon-specifically by phagocytosis to engulf microorganisms, incorporatethem into vacuoles, termed phagosomes, which fuse with granulescontaining myeloperoxidase to form phagolysosomes. In phagolysosomes theenzymatic activity of the myeloperoxidase leads to the formation ofhypochlorous acid, a potent bactericidal compound. Hypochlorous acid isoxidizing in itself, and reacts most avidly with thiols and thioethers,but also converts amines into chloramines, and chlorinates aromaticamino acids. Macrophages are large phagocytic cells which, like PMNs,are capable of phagocytosing microorganisms. Macrophages can generatehydrogen peroxide and upon activation also produce myeloperoxidase. MPOand hydrogen peroxide can also be released to the outside of the cellswhere the reaction with chloride can induce damage to adjacent tissue.

Linkage of myeloperoxidase activity to disease has been implicated inneurological diseases with a neuroinflammatory response includingmultiple sclerosis, Alzheimer's disease, Parkinson's disease and strokeas well as other inflammatory diseases or conditions like asthma,chronic obstructive pulmonary disease, cystic fibrosis, atherosclerosis,inflammatory bowel disease, renal glomerular damage and rheumatoidarthritis. Lung cancer has also been suggested to be associated withhigh MPO levels.

Multiple sclerosis (MS)

MPO positive cells are immensely present in the circulation and intissue undergoing inflammation. More specifically MPO containingmacrophages and microglia has been documented in the CNS during disease;multiple sclerosis (Nagra R M, et al. Journal of Neuroimmunology 1997;78(1-2):97-107), Parkinson's disease (Choi D-K. et al. J. Neurosci.2005; 25(28):6594-600) and Alzheimer's disease (Green P S. et al.Journal of Neurochemistry. 2004; 90(3):724-33). It is supposed that someaspects of a chronic ongoing inflammation result in an overwhelmingdestruction where agents from MPO reactions have an important role.

The enzyme is released both extracellularly as well as intophagolysosomes in the neutrophils (Hampton M B, Kettle A J, WinterbournC C. Blood 1998; 92(9):3007-17). A prerequisite for the MPO activity isthe presence of hydrogen peroxide, generated by NADPH oxidase and asubsequent superoxide dismutation. The oxidized enzyme is capable to usea plethora of different substrates of which chloride is most recognized.From this reaction the strong non-radical oxidant—hypochlorous acid(HOCl)—is formed. HOCl oxidizes sulphur containing amino acids likecysteine and methionine very efficiently (Peskin A V, Winterbourn C C.Free Radical Biology and Medicine 2001; 30(5):572-9). It also formschloramines with amino groups, both in proteins and other biomolecules(Peskin A V. et al. Free Radical Biology and Medicine 2004;37(10):1622-30). It chlorinates phenols (like tyrosine) (Hazen S L. etal. Mass Free Radical Biology and Medicine 1997; 23(6):909-16) andunsaturated bonds in lipids (Albert C J. et al. J. Biol. Chem. 2001;276(26):23733-41), oxidizes iron centers (Rosen H, Klebanoff S J.Journal of Biological Chemistry 1982; 257(22):13731-354) and crosslinksproteins (Fu X, Mueller D M, Heinecke J W. Biochemistry 2002;41(4):1293-301).

Proteolytic cascades participate both in cell infiltration through theBBB as well as the destruction of BBB, myelin and nerve cells (Cuzner ML, Opdenakker G. Journal of Neuroimmunology 1999; 94(1-2):1-14; Yong VW. et al. Nature Reviews Neuroscience 2001; 2(7):502-11). Activation ofmatrix metalloproteinases (MMPs) can be accomplished through the actionof upstream proteases in a cascade as well as through oxidation of adisulfide bridge Fu X. et al. J. Biol. Chem. 2001; 276(44):41279-87; GuZ. et al. Science 2002; 297(5584):1186-90). This oxidation can be eithera nitrosylation or HOCl-mediated oxidation. Both reactions can be aconsequence of MPO activity. Several reports have suggested a role forMMP's in general and MMP-9 in particular as influencing cellinfiltration as well as tissue damage (BBB breakdown and demyelination),both in MS and EAE (for review see Yong V W. et al, supra). Theimportance of these specific kinds of mechanisms in MS comes fromstudies where increased activity and presence of proteases have beenidentified in MS brain tissue and CSF. Supportive data has also beengenerated by doing EAE studies with mice deficient in some of theproteases implicated to participate in the MS pathology, or by usingpharmacological approaches.

The demyelination is supposed to be dependent on the cytotoxic T-cellsand toxic products generated by activated phagocytes (Lassmann H. JNeurol Neurosurg Psychiatry 2003; 74(6):695-7). The axonal loss is thusinfluenced by proteases and reactive oxygen and nitrogen intermediates.When MPO is present it will obviously have the capability of bothactivating proteases (directly as well as through disinhibition byinfluencing protease inhibitors) and generating reactive species.

Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD) is a disease statecharacterised by airflow limitation that is not fully reversible. Theairflow limitation is usually both progressive and associated with anabnormal inflammatory response of the lungs to noxious particles orgases. COPD is a major public health problem. It is the fourth leadingcause of chronic morbidity and mortality in the United States1 and isprojected to rank fifth in 2020 as a worldwide burden of disease. In theUK the prevalence of COPD is 1.7% in men and 1.4% in women. COPD spans arange of severity from mild to very severe, with the cost of treatmentrising rapidly as the severity increases.

Levels of MPO in sputum and BAL are much greater in COPD patients thatnormal, non-smoking controls (Keatings V. M., Barnes P. J. Am J RespirCrit Care Med 1997; 155:449-453; Pesci, A. et al. Eur Respir J 1998;12:380-386). MPO levels are further elevated during exacerbations of thedisease (Fiorini G. et al. Biomedicine & Pharmacotherapy 2000;54:274-278; Crooks S. W. et al. European Respiratory Journal.15(2):274-80, 2000). The role of MPO is likely to be more important inexacerbations of COPD (Sharon S. D. et al. Am J Respir Crit Care Med.2001; 163:349-355).

In addition to the destructive capacity of MPO there is a strongclinical link with vascular disease (Baldus S. et al. Circulation 2003;108:1440-5). Dysfunctional MPO polymorphisms are associated with areduced risk of mortality from coronary artery disease (Nikpoor B. etal. Am Heart J 2001; 142:336), and patients with high serum levels ofMPO have increased risk of acute coronary syndrome. The effects of MPOon vascular disease may extend to COPD, since there is strong evidencethat the pulmonary vasculature is one of the earliest sites ofinvolvement in the smokers' lung. Striking changes in the intima of thepulmonary arteries have been described which show a close relationshipwith smoking (Hale K. A., Niewoehner D. E., Cosio M. G. Am Rev Resp Dis1980; 122:273-8).

The physiological function of MPO is associated with innate hostdefence. This role, however, is not critical as most cases of MPOdeficient patients have relatively benign symptoms (Parry M. F. et al.Ann Int Med. 1981; 95:293-301, Yang, K. D., Hill, H. R. Pediatr InfectDis J. 2001; 20: 889-900). In summary, there is considerable evidencethat elevated MPO levels in COPD may contribute to the disease viaseveral mechanisms. A selective inhibitor of MPO would therefore beexpected to alleviate both the acute and chronic inflammatory aspects ofCOPD and may reduce the development of emphysema.

Atherosclerosis

An MPO inhibitor should reduce the atherosclerotic burden and/or thevulnerability of existing atherosclerotic lesions and thereby decreasethe risk of acute myocardial infarction, unstable angina or stroke.Several lines of data support a role for MPO in atherosclerosis. MPO isexpressed in the shoulder regions and necrotic core of humanatherosclerotic lesions and active enzyme has been isolated from autopsyspecimens of human lesions (Daugherty, A. et al. (1994) J Clin Invest94(1): 437-44). In eroded and ruptured human lesions, as compared tofatty streaks, an increased number of MPO expressing macrophages havebeen demonstrated, suggesting a particular role for MPO in acutecoronary syndromes (Sugiyama, S. et al. (2001) Am J Pathol 158(3):879-91). Patients with established coronary artery disease have higherplasma and leukocyte MPO levels than healthy controls (Zhang, R. et al.(2001) Jama 286(17): 2136-42). Moreover, in two large prospectivestudies plasma levels of MPO predicted the risk of future coronaryevents or revascularisation (Baldus, S. et al. (2003) Circulation108(12): 1440-5; Brennan, M. et al. (2003) N Engl J Med 349(17):1595-604). Total MPO deficiency in humans has a prevalece of 1 in2000-4000 individuals. These individuals appear principally healthy buta few cases of severe Candida infection have been reported.Interestingly, MPO deficient humans are less affected by cardiovasculardisease than controls with normal MPO levels (Kutter, D. et al. (2000)Acta Haematol 104(1)). A polymorphism in the MPO promoter affectsexpression leading to high and low MPO expressing individuals. In threedifferent studies the high expression genotype has been associated withan increased risk of cardiovascular disease (Nikpoor, B. et al. (2001)Am Heart J 142(2): 336-9; Makela, R., P. J. Karhunen, et al. (2003) LabInvest 83(7): 919-25; Asselbergs, F. W., et al. (2004) Am J Med 116(6):429-30). Data accumulated during the last ten years indicate that theproatherogenic actions of MPO include oxidation of lipoproteins,induction of endothelial dysfunction via consuming nitric oxide anddestabilisation of atherosclerotic lesions by activation of proteases(Nicholls, S. J. and S. L. Hazen (2005) Arterioscler Thromb Vasc Biol25(6): 1102-11). Recently, several studies have focused on nitro- andchlorotyrosine modifications of LDL and HDL lipoproteins. Sincechlorotyrosine modifications in vivo only can be generated byhypochlorus acid produced by MPO these modifiactions are regareded asspecific markers of MPO activity (Hazen, S. L. and J. W. Heinecke (1997)J Clin Invest 99(9): 2075-81). LDL particles exposed to MPO in vitrobecome aggregated, leading to facilitated uptake via macrophagescavenger receptors and foam cell formation (Hazell, L. J. and R.Stocker (1993) Biochem J 290 (Pt 1): 165-72). Chlorotyrosinemodification of apoA1, the main apolipoprotein of HDL cholesterol,results in impaired cholesterol acceptor function (Bergt, C., S. et al.(2004) Proc Natl Acad Sci USA; Zheng, L. et al. (2004) J Clin Invest114(4): 529-41). Systematic studies of these mechanisms have shown thatMPO binds to and travels with apoA1 in plasma. Moreover, MPOspecifically targets those tyrosine residues of apoA1 that physicallyinteract with the macrophage ABCA1 cassette transporter duringcholesterol efflux from the macrophage (Bergt, C. et al. (2004) J BiolChem 279(9): 7856-66; Shao, B. et al. (2005) J Biol Chem 280(7):5983-93; Zheng et al. (2005) J Biol Chem 280(1): 38-47). Thus, MPO seemsto have a dual aggravating role in atherosclerotic lesions, i.e.increasing lipid accumulation via aggregation of LDL particles anddecreasing the reverse cholesterol transport via attack on the HDLprotein apoA1.

1-β-D-Ribofuranosyl-2-oxopyrrolo[3,2-d]pyrimidine-4(3H,5H)-thione and1-(2,3,5-tri-O-benzoyl-1-β-D-ribofuranosyl)-2-oxopyrrolo[3,2-d]pyrimidine-4(3H,5H)-thione

are disclosed in J. Heterocyclic Chemistry, 1992, 29, 343-354. Nopharmacological activity is ascribed to these compounds.

5,7-Dimercapto-1,4,6-triazaindene

is disclosed in Chem. Pharm. Bull., 1964, 12, 1030-1042 and in Japanesepatent JP 02160235 A2. No pharmacological activity is ascribed to thiscompound.

The present invention discloses novel pyrrolo[3,2-d]pyrimidin-4-onederivatives that surprisingly display useful properties as inhibitors ofthe enzyme MPO. These compounds may also show selectivity againstrelated enzymes e.g. lactoperoxidase (LPO) and thyroidperoxidase (TPO).

DISCLOSURE OF THE INVENTION

The present invention provides compounds of formula (I)

wherein:

at least one of X and Y represents S, and the other represents 0 or S;

L represents a direct bond or C1 to 7 alkylene, said alkylene optionallyincorporating a heteroatom selected from O, S(O)_(n) and NR⁶, saidalkylene optionally incorporating one or two carbon-carbon double bonds,and said alkylene being optionally substituted by one or moresubstituents selected independently from OH, halogen, CN and NR⁴R⁵, C1to 6 alkyl and C1 to 6 alkoxy, said alkoxy optionally incorporating acarbonyl adjacent to the oxygen;

n represents an integer 0, 1 or 2;

R¹ represents hydrogen, or

i) a saturated or partially unsaturated 3 to 7 membered ring optionallyincorporating one or two heteroatoms selected independently from O, Nand S, and optionally incorporating a carbonyl group, optionallysubstituted by one or more substituents independently selected fromhalogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH, C1 to 7 alkyl, C1 to 7 alkoxy, CN,CONR²R³, NR²COR³ and COR³, said alkoxy being optionally furthersubstituted by C1 to 6 alkoxy and said alkoxy optionally incorporating acarbonyl adjacent to the oxygen, and said alkyl being optionally furthersubstituted by hydroxy or C1 to 6 alkoxy and said alkyl or alkoxyoptionally incorporating a carbonyl adjacent to the oxygen or at anyposition in the alkyl; or

ii) an aromatic ring system selected from phenyl, biphenyl, naphthyl ora monocyclic or bicyclic heteroaromatic ring structure containing 1 to 3heteroatoms independently selected from O, N and S, said aromatic ringsystem being optionally substituted by one or more substituentsindependently selected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH, C1 to 7alkyl, C1 to 7 alkoxy, CN, CONR²R³, NR²COR³ and COR³; said alkoxy beingoptionally further substituted by C1 to 6 alkoxy and said alkoxyoptionally incorporating a carbonyl adjacent to the oxygen, and saidalkyl being optionally further substituted by hydroxy or C1 to 6 alkoxyand said alkyl or alkoxy optionally incorporating a carbonyl adjacent tothe oxygen or at any position in the alkyl;

R¹² represents hydrogen or halogen or a carbon optionally substitutedwith one to three halogen atoms;

at each occurrence, R², R³, R⁴, R⁵, R⁶, R⁹ and R¹⁰ independentlyrepresent hydrogen, C1 to 6 alkyl or C1 to 6 alkoxy said alkoxyoptionally incorporating a carbonyl adjacent to the oxygen, said alkylbeing optionally further substituted by halogen, C1 to 6 alkoxy, CHO, C2to 6 alkanoyl, OH, CONR⁷R⁸ and NR⁷COR⁸;

or the groups NR²R³, NR⁴R⁵ and NR⁹R¹⁰ each independently represent a 5to 7 membered saturated azacyclic ring optionally incorporating oneadditional heteroatom selected from O, S and NR¹¹, said ring beingoptionally further substituted by halogen, C1 to 6 alkoxy, CHO, C2 to 6alkanoyl, OH, CONR⁷R⁸ and NR⁷COR⁸;

at each occurrence R⁷, R⁸ and R¹¹ independently represent hydrogen or C1to 6 alkyl, or the group NR⁷R⁸ represents a 5- to 7-membered saturatedazacyclic ring optionally incorporating one additional heteroatomselected from O, S and NR¹¹;

and pharmaceutically acceptable salts thereof;

with the proviso that the compounds1-β-D-ribofuranosyl-2-oxopyrrolo[3,2-d]pyrimidine-4(3H,5H)-thione,1-(2,3,5-tri-O-benzoyl-1-β-D-ribofuranosyl)-2-oxopyrrolo[3,2-d]pyrimidine-4(3H,5H)-thioneand 5,7-dimercapto-1,4,6-triazaindene are disclaimed.

The compounds of formula (I) may exist in enantiomeric forms. It is tobe understood that all enantiomers, diastereomers, racemates, tautomersand mixtures thereof are included within the scope of the invention.

The compounds of formula (I) may exist in tautomeric forms. All suchtautomers and mixtures of tautomers are included within the scope of thepresent invention.

Unless otherwise indicated, the term “C1 to 6 alkyl” referred to hereindenotes a straight or branched chain alkyl group having from 1 to 6carbon atoms. Examples of such groups include, but are not limited to,methyl, ethyl, 1-propyl, n-butyl, iso-butyl, tert-butyl, pentyl andhexyl. The term “C1 to 7 alkyl” is to be interpreted analogously

Unless otherwise indicated, the term “C1 to 7 alkylene” referred toherein denotes a straight or branched chain alkyl group having from 1 to7 carbon atoms having two free valencies. Examples of such groupsinclude, but are not limited to, methylene, ethylene, propylene,hexamethylene and ethylethylene. The term “C1 to 3 alkylene” is to beinterpreted analogously.

Unless otherwise indicated, the term “C1 to 6 alkoxy” referred to hereindenotes a straight or branched chain alkoxy group having from 1 to 6carbon atoms. Examples of such groups include, but are not limited to,methoxy, ethoxy, 1-propoxy, 2-propoxy (iso-propoxy), tert-butoxy andpentoxy. The term “C1 to 7 alkoxy” is to be interpreted analogously.

Unless otherwise indicated, the term “C2 to 6 alkanoyl” referred toherein denotes a straight or branched chain alkyl group having from 1 to5 carbon atoms with optional position on the alkyl group by a carbonylgroup. Examples of such groups include, but are not limited to, acetyl,propionyl and pivaloyl.

Unless otherwise indicated, the term “halogen” referred to hereindenotes fluoro, chloro, bromo and iodo.

Examples of a saturated or partially unsaturated 3- to 7-membered ringoptionally incorporating one or two heteroatoms selected independentlyfrom O, N and S, and optionally incorporating a carbonyl group includes,but is not limited to, cyclopropane, cyclopentane, cyclohexane,cyclohexene, cyclopentanone, tetrahydrofuran, pyrrolidine, piperidine,tetrahydropyridine, morpholine, piperazine, pyrrolidinone andpiperidinone.

Examples of a monocyclic or bicyclic heteroaromatic ring structurecontaining 1 to 3 heteroatoms independently selected from O, N and Sincludes, but is not limited to, furan, thiophene, pyrrole, oxazole,isoxazole, thiazole, imidazole, pyrazole, triazole, tetrazole, pyridine,pyrazine, pyrimidine, pyridazine, benzofuran, indole, isoindole andbenzimidazole.

Examples of a 5 to 7 membered saturated azacyclic ring optionallyincorporating one additional heteroatom selected from O, S and NR¹¹includes, but is not limited to, pyrrolidine, piperidine, piperazine,morpholine and thiomorpholine.

In the definition of L, “C1 to 7 alkylene; said alkylene optionallyincorporating a heteroatom selected from O, S(O)_(n) and NR⁶; saidalkylene optionally incorporating one or two carbon-carbon double bonds”embraces a saturated or unsaturated straight or branched chainarrangement of 1 to 7 carbon atoms having two free valencies and inwhich any two singly bonded carbon atoms are optionally separated by O,S or NR⁶. The definition thus includes, for example, methylene,ethylene, propylene, hexamethylene, ethylethylene, —CH₂═CH₂—,—CH₂CH═CH—CH₂—, —CH(CH₃)═CH₂—, —CH₂═CH₂—CH₂O—, —CH₂O—, —CH₂CH₂O—CH₂—,—CH₂CH₂O—CH₂—CH₂—, —CH₂CH₂S— and —CH₂CH₂NR⁶—.

In one embodiment, R¹ represents hydrogen.

In another embodiment, X represents S and Y represents O.

In yet another embodiment, Y represents S and X represents O.

In yet another embodiment, L is a direct bond or represents C1 to 7alkylene, said alkylene optionally incorporating a heteroatom selectedfrom O, S(O)_(n) and NR⁶, said alkylene optionally incorporating one ortwo carbon-carbon double bonds, and said alkylene being optionallysubstituted by one or more substituents selected independently from OH,C1 to 6 alkoxy, halogen, CN and NR⁴R⁵.

In yet another embodiment, L is a direct bond or represents C1 to 7alkylene; said alkylene being optionally substituted by one or moresubstituents selected independently from OH, C1 to 6 alkoxy, halogen, CNand NR⁴R⁵.

In yet another embodiment, L is a direct bond or represents C1 to 7alkylene; said alkylene being optionally substituted by one or more C1to 6 alkoxy.

In yet another embodiment, L is a direct bond or represents C1 to 3alkylene; said alkylene being optionally substituted by one or moresubstituents selected independently from OH, C1 to 6 alkoxy, halogen, CNand NR⁴R⁵.

In yet another embodiment, L represents C1 to 3 alkylene; said alkylenebeing optionally substituted by one or more C1 to 6 alkoxy.

In yet another embodiment, L is a direct bond or represents optionallysubstituted methylene (—CH₂—).

In yet another embodiment, L is a direct bond or represents optionallysubstituted ethylene (—CH₂CH₂—).

In yet another embodiment, R¹ represents a saturated or partiallyunsaturated 3 to 7 membered ring optionally incorporating one or twoheteroatoms selected independently from O, N and S, and optionallyincorporating a carbonyl group, said ring being optionally substitutedby one or more substituents independently selected from halogen, SO₂R⁹,SO₂NR⁹R¹⁰, OH, C1 to 6 alkyl, C1 to 6 alkoxy, CN, CONR²R³, NR²COR³ andCOR³, said alkoxy being optionally further substituted by C1 to 6alkoxy; and said alkyl being optionally further substituted by hydroxyor C1 to 6 alkoxy.

In yet another embodiment, R¹ represents a saturated or partiallyunsaturated 3 to 7 membered ring optionally incorporating one or twoheteroatoms selected independently from O, N and S, and optionallyincorporating a carbonyl group; said ring being optionally substitutedby one or more substituents independently selected from halogen, C1 to 6alkyl and C1 to 6 alkoxy, said alkoxy being optionally furthersubstituted by C1 to 6 alkoxy.

In yet another embodiment, R¹ represents an aromatic ring systemselected from phenyl, biphenyl, naphthyl or a monocyclic or bicyclicheteroaromatic ring structure containing 1 to 3 heteroatomsindependently selected from O, N and S, said aromatic ring beingoptionally substituted by one or more substituents independentlyselected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH, C1 to 6 alkyl, C1 to 6alkoxy, CN, CONR²R³, NR²COR³ and COR³, said alkoxy being optionallyfurther substituted by C1 to 6 alkoxy, and said alkyl being optionallyfurther substituted by hydroxy or C1 to 6 alkoxy.

In yet another embodiment, R¹ represents an aromatic ring systemselected from phenyl, biphenyl, naphthyl or a five- or six-memberedheteroaromatic ring containing 1 to 3 heteroatoms independently selectedfrom O, N and S, said aromatic ring being optionally substituted by oneor more substituents independently selected from halogen, C1 to 6 alkyland C1 to 6 alkoxy, said alkoxy being optionally further substituted byC1 to 6 alkoxy.

In yet another embodiment, R¹ represents an optionally substitutedphenyl.

In yet another embodiment, R¹ represents an optionally substitutedpyridyl.

In yet another embodiment, L represents C1 to 7 alkylene and R¹represents H.

In yet another embodiment, L represents an optionally substituted C1 to3 alkylene and R¹ represents a saturated or partially unsaturated 3- to7-membered ring optionally incorporating one or two heteroatoms selectedindependently from O, N and S, and optionally incorporating a carbonylgroup, said ring being optionally substituted by one or moresubstituents independently selected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH,C1 to 6 alkyl, C1 to 6 alkoxy, CN, CONR²R³, NR²COR³ and COR³, saidalkoxy being optionally further substituted by C1 to 6 alkoxy, and saidalkyl being optionally further substituted by hydroxy or C1 to 6 alkoxy.

In yet another embodiment, L represents an optionally substituted C1 to3 alkylene and R¹ represents a saturated or partially unsaturated 3- to7-membered ring optionally incorporating one or two heteroatoms selectedindependently from O, N and S, and optionally incorporating a carbonylgroup, said ring being optionally substituted by one or moresubstituents independently selected from halogen, C1 to 6 alkyl and C1to 6 alkoxy, said alkoxy being optionally further substituted by C1 to 6alkoxy.

In yet another embodiment, L represents optionally substituted C1 to 3alkylene and R¹ represents an aromatic ring system selected from phenyl,biphenyl, naphthyl or a five- or six-membered heteroaromatic ringcontaining 1 to 3 heteroatoms independently selected from O, N and S;said aromatic ring being optionally substituted by one or moresubstituents independently selected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH,C1 to 6 alkyl, C1 to 6 alkoxy, CN, CONR²R³, NR²COR³ and COR³, saidalkoxy being optionally further substituted by C1 to 6 alkoxy, and saidalkyl being optionally further substituted by hydroxy or C1 to 6 alkoxy.

In yet another embodiment, L represents optionally substituted C1 to 3alkylene and R¹ represents an aromatic ring system selected from phenyl,biphenyl, naphthyl or a five- or six-membered heteroaromatic ringcontaining 1 to 3 heteroatoms independently selected from O, N and S,said aromatic ring being optionally substituted by one or moresubstituents independently selected from halogen, C1 to 6 alkyl and C1to 6 alkoxy, said alkoxy being optionally further substituted by C1 to 6alkoxy.

In yet another embodiment, X represents S, Y represents O, L representsoptionally substituted C1 to 3 alkylene and R¹ represents optionallysubstituted phenyl.

In yet another embodiment, X represents S, Y represents O, L representsoptionally substituted C1 to 3 alkylene and R¹ represents optionallysubstituted pyridyl.

In yet another embodiment, X represents S, Y represents O, L representsC1 to 3 alkylene, substituted with C1 to 6 alkoxy and R¹ representshydrogen.

Particular compounds of the invention include:

-   1-butyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-fluoro-benzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[2-(2-methoxyethoxy)-3-propoxybenzyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(6-ethoxy-pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-piperidin-3-ylmethyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-butyl-4-thioxo-1,3,4,5-tetrahydro-2H-pyrrolo[3,2-d]pyrimidin-2-one;-   1-(2-isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-methoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-ethoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(piperidin-4-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(1-methylpiperidin-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[2-hydroxy-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(3-methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2,4-dimethoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(3-chloropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{[3-(2-ethoxyethoxyl)pyridin-2-yl]methyl}-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(6-oxo-1,6-dihydropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(1H-indol-3-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(1H-benzimidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(5-chloro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(5-fluoro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(1H-indol-6-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(1H-indol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(5-fluoro-1H-indol-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-c]pyrimidin-4-one;-   1-(1H-imidazol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(1H-imidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(5-chloro-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[(4,5-dimethyl-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;-   7-bromo-1-isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one;    and-   1-(3-chlorophenyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one.

and pharmaceutically acceptable salts thereof.

A further aspect of the invention is the use of the novel compounds offormula (I) as a medicament.

A further aspect of the invention is the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament, for the treatment or prophylaxis of diseases orconditions in which inhibition of the enzyme MPO is beneficial.

A further aspect of the invention provides the use of a compound offormula (I), or a pharmaceutically acceptable salt thereof, in themanufacture of a medicament, for the treatment or prophylaxis ofneuroinflammatory disorders, cardio- and cerebrovascular atheroscleroticdisorders and peripheral artery disease and respiratory disorders suchas chronic obstructive pulmonary disease.

Another further aspect of the invention provides the use of a compoundof formula (I), or a pharmaceutically acceptable salt thereof, in themanufacture of a medicament, for the treatment or prophylaxis ofmultiple sclerosis. Treatment may include slowing progression ofdisease.

Another further aspect of the present invention provides the use of acompound of formula (I) or a pharmaceutically acceptable salt thereof,in the manufacture of a medicament, for the treatment or prophylaxis ofatherosclerosis by preventing and/or reducing the formation of newatherosclerotic lesions or plaques and/or by preventing or slowingprogression of existing lesions and plaques.

Another further aspect of the present invention provides the use of acompound of formula (I) or a pharmaceutically acceptable salt thereof,in the manufacture of a medicament, for the treatment or prophylaxis ofatherosclerosis by changing the composition of the plaques to reduce therisk of plaque rupture and atherothrombotic events.

Another further aspect of the present invention provides the use of acompound of formula (I) or a pharmaceutically acceptable salt thereof,in the manufacture of a medicament, for the treatment or prophylaxis ofrespiratory disorders, such as chronic obstructive pulmonary disease.Treatment may include slowing progression of disease.

According to the invention, there is also provided a method of treating,or reducing the risk of, diseases or conditions in which inhibition ofthe enzyme MPO is beneficial which comprises administering to a personsuffering from or at risk of, said disease or condition, atherapeutically effective amount of a compound of formula (I), or apharmaceutically acceptable salt thereof.

Further, there is also provided a method of treating, or reducing therisk of, neuroinflammatory disorders, cardio- and cerebrovascularatherosclerotic disorders or peripheral artery disease, or respiratorydisorders, such as chronic obstructive pulmonary disease, in a personsuffering from or at risk of, said disease or condition, wherein themethod comprises administering to the person a therapeutically effectiveamount of a compound of formula (I), or a pharmaceutically acceptablesalt thereof.

Further, there is also provided a method of treating, or reducing therisk of, multiple sclerosis in a person suffering from or at risk of,said disease or condition, wherein the method comprises administering tothe person a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

There is also provided a method of treating, or reducing the risk ofatherosclerosis by preventing and/or reducing the formation of newatherosclerotic lesions or plaques and/or by preventing or slowingprogression of existing lesions and plaques in a person suffering fromor at risk of, said disease or condition, wherein the method comprisesadministering to the person a therapeutically effective amount of acompound of formula (I) or a pharmaceutically acceptable salt thereof.

There is also provided a method of treating, or reducing the risk ofatherosclerosis by changing the composition of the plaques so as toreduce the risk of plaque rupture and atherothrombotic events in aperson suffering from or at risk of, said disease or condition, whereinthe method comprises administering to the person a therapeuticallyeffective amount of a compound of formula (I) or a pharmaceuticallyacceptable salt thereof.

In another aspect the invention provides a pharmaceutical formulationcomprising a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use in thetreatment or prophylaxis of diseases or conditions in which inhibitionof the enzyme MPO is beneficial.

In a further aspect the invention provides a pharmaceutical formulationcomprising a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use in thetreatment or prophylaxis of neuroinflammatory disorders.

In a further aspect the invention provides a pharmaceutical formulationcomprising a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use in thetreatment or prophylaxis of multiple sclerosis, cardio- andcerebrovascular atherosclerotic disorders and peripheral artery diseaseand respiratory disorders, such as chronic obstructive pulmonarydisease.

In another aspect the present invention provides a pharmaceuticalformulation comprising a therapeutically effective amount of a compoundof formula (I), or a pharmaceutically acceptable salt thereof, inadmixture with a pharmaceutically acceptable adjuvant, diluent orcarrier, for use in the treatment or prophylaxis of atherosclerosis bypreventing and reducing the formation of new atherosclerotic lesionsand/or plaques and/or by preventing or slowing progression of existinglesions and plaques.

In another aspect the present invention provides a pharmaceuticalformulation comprising a therapeutically effective amount of a compoundof formula (I), or a pharmaceutically acceptable salt thereof, inadmixture with a pharmaceutically acceptable adjuvant, diluent orcarrier, for use in the treatment or prophylaxis of atherosclerosis bychanging the composition of the plaques so as to reduce the risk ofplaque rupture and atherothrombotic events.

According to the invention, there is further provided a process for thepreparation of the novel compounds of formula (I), or a pharmaceuticallyacceptable salt, tautomer, enantiomer, diastereomer or racemate thereofwhich comprises reaction of a compound of formula (II),

wherein R¹, R¹² and L are as defined in formula (I) and R represents C1to 6 alkoxy with the oxygen in a direct bond to the carbonyl in formula(II) with alkoxy as defined above or NH₂; with a C1 to 6 alkoxycarbonylisothiocyanate or with a phenylcarbonyl isothiocyanate, wherein thephenyl group is optionally substituted by one or more groups selectedindependently from C1 to 6 alkyl, halogen, C1 to 6 alkoxy, NO₂, OH, CN,C1 to 6 alkylamino or NH₂; and where necessary converting the resultantcompound of formula (I), or another salt thereof, into apharmaceutically acceptable salt thereof; or converting the resultantcompound of formula (I) into a further compound of formula (I); andwhere desired converting the resultant compound of formula (I) into anoptical isomer thereof.

In the process, a compound of formula (II) and the alkoxycarbonylisothiocyanate or the phenylcarbonyl isothiocyanate are dissolved orsuspended in a suitable dry organic solvent such as dichloromethane orand stirred at 0 to 30 degrees for example at ambient temperature untilreaction is complete, typically for between 5 to 60 minutes, but ifnecessary, overnight. Preferably the alkoxycarbonyl isothiocyanate isethoxycarbonyl isothiocyanate and the phenylcarbonyl isothiocyanate ispreferably benzoyl isothiocyanate. Following a standard work-up theintermediate product is then optionally purified before treatment with abase, such as sodium ethoxide in ethanol, aqueous sodium hydroxide orammonia in solution, ammonia in methanol, to give the required compoundof formula (I). The cyclization is carried out at an elevatedtemperature either in an oil bath or in a microwave reactor. See, forexample, Norman et al, J. Med. Chem. 2000, 43, 4288-4312. When ammoniain methanol is used, a pressure vessel is preferably used.

Compounds of formula (II) may be prepared by reaction of a compound offormula (III), wherein R¹² is as defined in Formula I, R is as definedin formula II (see for example Furneaux et al, J. Org. Chem. 1999, 64,8411-8412), and may be carried out by

a) reductive amination. In the process, a compound of formula (III) maybe mixed with an aldehyde of formula (IV), wherein R¹ is defined as informula I, in the presence of a reducing agent such as sodiumcyanoborohydride or sodium triacetoxyborohydride. An acid, preferablyacetic acid, may be added to catalyze the reaction. The reaction may beperformed in a solvent such as methanol between ambient temperature and50° C., preferably at ambient temperature.

Following a standard work-up the product is then optionally purified byflash column chromatography. See for example Suzuki et al, Chem. Pharm.Bull. 2002, 50, 1163-1168, or Furneaux, R. H., Tyler, P. C., J. Org.Chem. 1999, 64, 8411-8412.

b) alkylation. In the process, a mesylate of formula (V), wherein R¹ isdefined as above, may be added to a stirred solution of a compound offormula (III), potassium iodide and a base, preferably potassiumcarbonate. The reaction may be performed in a solvent, such asN,N-dimethylformamide, at an elevated reaction temperature, preferablyat 85° C. The reaction mixture may be worked up by extraction and thenpurified by flash column chromatography to give a compound of formula(II).

c) cross-coupling of a compound of formula (III) with a suitable aryl ofa compound (VI), wherein R¹ is defined as above and Halo is halogen,preferably bromo, to give a compound of formula (II). The reaction maybe carried out using a suitable palladium catalyst such as Pd₂(dba)₃ orPd(OAc)₂ together with a suitable ligand such as BINAP. A suitable base,such as cesium carbonate, may be used in the reaction in a suitablesolvent such as tetrahydrofuran, dioxane or toluene, which is performedin the temperature range between 80° C. and 100° C. See for example, J.P. Wolfe, S. L. Buchwald J. Org. Chem. 2000, 65, 1144-1157.

Compounds of formula (II) are either known in the literature or may beprepared using known methods that will be readily apparent to the manskilled in the art. See, for example, Suzuki et al, Chem. Pharm. Bull.2002, 50, 1163-1168, or Furneaux, R. H., Tyler, P. C., J. Org. Chem.1999, 64, 8411-8412.

Compounds of formula (IV), (V) and (VI) are either commerciallyavailable or may be prepared using methods that are well-known in theliterature.

The present invention includes compounds of formula (I) in the form ofsalts. Suitable salts include those formed with organic or inorganicacids or organic or inorganic bases. Such salts will normally bepharmaceutically acceptable although salts of non-pharmaceuticallyacceptable acids or bases may be of utility in the preparation andpurification of the compound in question. Thus, preferred acid additionsalts include those formed from hydrochloric, hydrobromic, sulphuric,phosphoric, citric, tartaric, lactic, pyruvic, acetic, succinic,fumaric, maleic, methanesulphonic and benzenesulphonic acids. Preferredbase addition salts include those in which the cation is sodium,potassium, calcium, aluminium, lithium, magnesium, zinc, choline,ethanolamine or diethylamine.

Salts of compounds of formula (I) may be formed by reacting thecompound, or a salt, enantiomer or racemate thereof, with one or moreequivalents of the appropriate acid or base. The reaction may be carriedout in a solvent or medium in which the salt is insoluble or in asolvent in which the salt is soluble, for example, water, dioxan,ethanol, tetrahydrofuran or diethyl ether, or a mixture of solvents,which may be removed in vacuo or by freeze drying. The reaction may alsobe a metathetical process or it may be carried out on an ion exchangeresin.

The compounds of the invention and intermediates thereto may be isolatedfrom their reaction mixtures and, if necessary further purified, byusing standard techniques.

The compounds of formula (I) may exist in enantiomeric forms. Therefore,all enantiomers, diastereomers, racemates, tautomers and mixturesthereof are included within the scope of the invention. The variousoptical isomers may be isolated by separation of a racemic mixture ofthe compounds using conventional techniques, for example, fractionalcrystallisation, or HPLC. Alternatively, the various optical isomers maybe prepared directly using optically active starting materials.

Intermediate compounds may also exist in enantiomeric forms and may beused as purified enantiomers, diastereomers, racemates or mixtures.

The compounds of formula (I) may exist in tautomeric forms. All suchtautomers and mixtures of tautomers are included within the scope of theinvention.

Intermediate compounds may also exist in tautomeric forms and may beused as purified tautomers or mixtures.

The compounds of formula (I) and their pharmaceutically acceptable saltsare useful because they possess pharmacological activity as inhibitorsof the enzyme MPO.

The compounds of formula (I) and their pharmaceutically acceptable saltsare indicated for use in the treatment or prophylaxis of diseases orconditions in which modulation of the activity of the enzymemyeloperoxidase (MPO) is desirable. In particular, linkage of MPOactivity to disease has been implicated in neuroinflammatory diseases.Therefore the compounds of the present invention are particularlyindicated for use in the treatment of neuroinflammatory conditions ordisorders in mammals including man. The compounds are also indicated tobe useful in the treatment of cardio- and cerebrovascularatherosclerotic disorders or peripheral artery disease. The compoundsare also indicated to be useful in the treatment of respiratorydisorders, such as disorders of the respiratory tract: obstructivediseases of the airways including: asthma, including bronchial,allergic, intrinsic, extrinsic, exercise-induced, drug-induced(including aspirin and NSAID-induced) and dust-induced asthma, bothintermittent and persistent and of all severities, and other causes ofairway hyper-responsiveness; chronic obstructive pulmonary disease(COPD); bronchitis, including infectious and eosinophilic bronchitis;emphysema; bronchiectasis; cystic fibrosis; sarcoidosis; farmer's lungand related diseases; hypersensitivity pneumonitis; lung fibrosis,including cryptogenic fibrosing alveolitis, idiopathic interstitialpneumonias, fibrosis complicating anti-neoplastic therapy and chronicinfection, including tuberculosis and aspergillosis and other fungalinfections; complications of lung transplantation; vasculitic andthrombotic disorders of the lung vasculature, and pulmonaryhypertension; antitussive activity including treatment of chronic coughassociated with inflammatory and secretory conditions of the airways,and iatrogenic cough; acute and chronic rhinitis including rhinitismedicamentosa, and vasomotor rhinitis; perennial and seasonal allergicrhinitis including rhinitis nervosa (hay fever); nasal polyposis; acuteviral infection including the common cold, and infection due torespiratory syncytial virus, influenza, coronavirus (including SARS) andadenovirus. Such conditions or disorders will be readily apparent to theman skilled in the art.

Conditions or disorders that may be specifically mentioned includemultiple sclerosis, Alzheimer's disease, Parkinson's disease,amyotrophic lateral sclerosis and stroke, as well as other inflammatorydiseases or conditions such as asthma, chronic obstructive pulmonarydisease, cystic fibrosis, idiopathic pulmonary fibrosis, acuterespiratory distress syndrome, sinusitis, rhinitis, psoriasis,dermatitis, uveitis, gingivitis, atherosclerosis, myocardial infarction,stroke, coronary heart disease, ischaemic heart disease, restenosis,inflammatory bowel disease, renal glomerular damage, liver fibrosis,sepsis, proctitis, rheumatoid arthritis, and inflammation associatedwith reperfusion injury, spinal cord injury and tissuedamage/scarring/adhesion/rejection. Lung cancer has also been suggestedto be associated with high MPO levels. The compounds are also expectedto be useful in the treatment of pain.

Prophylaxis is expected to be particularly relevant to the treatment ofpersons who have suffered a previous episode of, or are otherwiseconsidered to be at increased risk of, the disease or condition inquestion. Persons at risk of developing a particular disease orcondition generally include those having a family history of the diseaseor condition, or those who have been identified by genetic testing orscreening to be particularly susceptible to developing the disease orcondition.

For the above-mentioned therapeutic indications, the dosage administeredwill, of course, vary with the compound employed, the mode ofadministration and the treatment desired. However, in general,satisfactory results are obtained when the compounds are administered ata dosage of the solid form of between 1 mg and 2000 mg per day.

The compounds of formulae (I), and pharmaceutically acceptablederivatives thereof, may be used on their own, or in the form ofappropriate pharmaceutical compositions in which the compound orderivative is in admixture with a pharmaceutically acceptable adjuvant,diluent or carrier. Thus, another aspect of the invention concerns apharmaceutical composition comprising a novel compound of formula (I),or a pharmaceutically acceptable salt thereof, in admixture with apharmaceutically acceptable adjuvant, diluent or carrier. Administrationmay be by, but is not limited to, enteral (including oral, sublingual orrectal), intranasal, inhalation, intravenous, topical or otherparenteral routes. Conventional procedures for the selection andpreparation of suitable pharmaceutical formulations are described in,for example, “Pharmaceuticals—The Science of Dosage Form Designs”, M. E.Aulton, Churchill Livingstone, 1988. The pharmaceutical compositionpreferably comprises less than 80% and more preferably less than 50% ofa compound of formulae (I), or a pharmaceutically acceptable saltthereof.

There is also provided a process for the preparation of such apharmaceutical composition which comprises mixing the ingredients.

Examples of Pharmaceutical Composition

The following illustrate representative pharmaceutical dosage formscontaining a compound of formula I, or salts, solvates or solvated saltsthereof, (hereafter compound X), for preventive or therapeutic use inmammals:

(a): Tablet mg/tablet Compound X 100 Lactose 182.75 Croscarmellosesodium 12.0 Maize starch paste (5% w/v paste) 2.25 Magnesium stearate3.0 (b): Capsule mg/capsule Compound X 10 Lactose 488.5 Magnesiumstearate 1.5 (c): Injection (50 mg/ml) Compound X 5.0% w/v 1M Sodiumhydroxide solution 15.0% v/v   0.1M Hydrochloric acid (to adjust pH to7.6) Polyethylene glycol 400 4.5% w/v Water for injection up to 100%

The above compositions may be obtained by conventional procedures wellknown in the pharmaceutical art.

The invention further relates to combination therapies wherein acompound of formula (I) or a pharmaceutically acceptable salt thereof,or a pharmaceutical composition or formulation comprising a compound offormula (I), is administered concurrently or sequentially with therapyand/or an agent for the treatment of any one of cardio- andcerebrovascular atherosclerotic disorders and peripheral artery disease.

In particular, a compound of formula (I) or a pharmaceuticallyacceptable salt thereof may be administered in association withcompounds from one or more of the following groups:

1) anti-inflammatory agents, for example

-   -   a) NSAIDs (e.g. acetylsalicylic acid, ibuprofen, naproxen,        flurbiprofen, diclofenac, indometacin);    -   b) leukotriene synthesis inhibitors (5-LO inhibitors e.g.        AZD4407, Zileuton, licofelone, CJ13610, CJ13454; FLAP inhibitors        e.g. BAY-Y-1015, DG-031, MK591, MK886, A81834; LTA4 hydrolase        inhibitors e.g. SC56938, SC57461A);    -   c) leukotriene receptor antagonists (e.g. CP195543, amelubant,        LY293111, accolate, MK571);

2) anti-hypertensive agents, for example

-   -   a) beta-blockers (e.g. metoprolol, atenolol, sotalol);    -   b) angiotensin converting enzyme inhibitors (e.g. captopril,        ramipril, quinapril, enalapril);    -   c) calcium channel blockers (e.g. verapamil, diltiazem,        felodipine, amlodipine);    -   d) angiotensin II receptor antagonists (e.g. irbesartan,        candesartan, telemisartan, losartan);

3) anti-coagulantia, for example

-   -   a) thrombin inhibitors (e.g. ximelagatran), heparines, factor Xa        inhibitors;    -   b) platelet aggregation inhibitors (e.g. clopidrogrel,        ticlopidine, prasugel, AZ4160);

4) modulators of lipid metabolism, for example

-   -   a) insulin sensitizers such as PPAR agonists (e.g. pioglitazone,        rosiglitazone, Galida, muraglitazaar, gefemrozil, fenofibrate);    -   b) HMG-CoA reductase inhibitors, statins (e.g. simvastatin,        pravastatin, atorvaststin, rosuvastatin, fluvastatin);    -   c) cholesterol absorption inhibitors (e.g. ezetimibe);    -   d) IBAT inhibitors (e.g. AZD-7806);    -   e) LXR agonists (e.g. GW-683965A, T-0901317);    -   f) FXR receptor modulators;    -   g) phospholipase inhibitors;

5) anti-anginal agents, for example, nitrates and nitrites;

6) modulators of oxidative stress, for example, anti-oxidants(probucol).

General Methods

All solvents used were analytical grade and commercially availableanhydrous solvents were routinely used for reactions. Reactions weretypically run under an inert atmosphere of nitrogen or argon.

¹H and ¹³C NMR spectra were recorded at 400 MHz for proton and 100 MHzfor carbon-13 either on a Varian Unity+400 NMR Spectrometer equippedwith a 5 mm BBO probe head with Z-gradients, or a Bruker Avance 400 NMRspectrometer equipped with a 60 μl dual inverse flow probe head withZ-gradients, or a Bruker DPX400 NMR spectrometer equipped with a4-nucleus probe head equipped with Z-gradients. Unless specificallynoted in the examples, spectra were recorded at 400 MHz for proton and100 MHz for carbon-13. The following reference signals were used: themiddle line of DMSO-d₆ δ 2.50 (¹H), δ 39.51 (¹³C); the middle line ofCD₃OD δ 3.31 (¹H) or δ 49.15 (¹³C); acetone-d₆ 2.04 (¹H), 206.5 (¹³C);and CDCl₃ δ 7.26 (¹H), the middle line of CDCl₃ δ 77.16 (¹³C) (unlessotherwise indicated).

Mass spectra were recorded on a Waters LCMS consisting of an Alliance2795 (LC), Waters PDA 2996, and ELS detector (Sedex 75) and a ZMD singlequadrupole mass spectrometer. The mass spectrometer was equipped with anelectrospray ion source (ES) operated in a positive or negative ionmode. The capillary voltage was 3 kV and cone voltage was 30 V. The massspectrometer was scanned between m/z 100-600 with a scan time of 0.7 s.The column temperature was set to 40° C. The Diode Array Detector wasscanned from 200-400 nm. The temperature of the ELS detector wasadjusted to 40° C. and the pressure was set to 1.9 bar. For LCseparation a linear gradient was applied starting at 100% A (A: 10 mMNH₄OAc in 5% MeCN) and ending at 100% B (B: MeCN) after four minutes.The column used was a X-Terra MS C8, 3.0×50; 3.5 μm (Waters) run at 1.0mL/min.

Alternatively, mass spectra was performed on a GC-MS (GC 6890, 5973NMSD) supplied by Agilent Technologies. The column used was a VF-5 MS, ID0.25 mm×30 m, 0.25 μm (Varian Inc.). A linear temperature gradient wasapplied starting at 40° C. (hold 1 min) and ending at 300° C. (hold 1min), 25° C./minute. The MS was equipped with a CI ion source and thereactant gas was methane. The MS was scanned between m/z 50-500 and thescan speed was set to 3.25 scan/s. The MS was equipped with an EI ionsource. The MS was scanned between m/z 50-500 and the scan speed was setto 3.25 scan/s. The electron voltage was set to 70 eV.

HPLC analyses were performed on an Agilent HP1100 system consisting ofG1379A Micro Vacuum Degasser, G1312A Binary Pump, G1367A Well plateauto-sampler, G1316A Thermostatted Column Compartment and G1315B DiodeArray Detector. Column: X-Terra MS, Waters, 3.0×100 mm, 3.5 μm. Thecolumn temperature was set to 40° C. and the flow rate to 1.0 ml/min.The Diode Array Detector was scanned from 210-300 nm, step and peakwidth were set to 2 nm and 0.05 min, respectively. A linear gradient wasapplied, starting at 100% A (A: 10 mM NH₄OAc in 5% MeCN) and ending at100% B (B: MeCN), in 6 min.

Microwave heating was performed in an Initiator or Smith SynthesizerSingle-mode microwave cavity producing continuous irradiation at 2450MHz.

A typical workup procedure after a reaction consisted of extraction ofthe product with a solvent such as ethyl acetate, washing with waterfollowed by drying of the organic phase over MgSO₄ or Na₂SO₄ filtrationand concentration of the solution in vacuo.

Thin layer chromatography (TLC) was performed on Merck TLC-plates(Silica gel 60 F₂₅₄) and UV visualized the spots. Flash columnchromatography was preformed on a Combi Flash® Companion™ using RediSep™normal-phase flash columns. Typical solvents used for flash columnchromatography were mixtures of chloroform/methanol,dichloromethane/methanol and heptane/ethyl acetate.

Preparative chromatography was run on a Waters autopurification HPLCwith a diode array detector. Column: XTerra MS C8, 19×300 mm, 10 μm.Narrow gradients with MeCN/(95:5 0.1M NH₄OAc:MeCN) were used at a flowrate of 20 ml/min. Alternatively, another column was used; Atlantis C1819×100 mm, 5 μm column. Gradient with acetonitrile/0.1M ammonium acetatein 5% acetonitrile in MilliQ Water, run from 0% to 35-50% acetonitrile,in 15 min. Flow rate: 15 ml/min. Alternatively, purification wasachieved on a semi preparative Shimadzu LC-8A HPLC with a ShimadzuSPD-10A UV-vis.-detector equipped with a Waters Symmetry® column (C18, 5μm, 100 mm×19 mm). Narrow gradients with MeCN/0.1% trifluoroacetic acidin MilliQ Water were used at a flow rate of 10 ml/min.

Recrystallization was typically performed in solvents or solventmixtures such as ether, ethyl acetate/heptane and methanol/water.

The following abbreviations have been used:

aq. aqueous;

BINAP 2,2′bis(diphenylphosphino)-1,1′binaphtyl

equiv. equivalent;

DMF N,N-dimethylformamide;

DMSO dimethylsulfoxide;

DIBAL diisobutylaluminium hydride;

Et₃N triethyl amine;

HOAc acetic acid;

NaBH₄ sodium borohydride;

NaCNBH₃ sodium cyanoborohydride;

Pd₂(dba)₃ tris(dibenaylideneacetone)dipalladium;

Pd(OAc)₂ palladium diacetate;

r.t. room temperature;

TBDMSCl tert-butyldimethylsilyl chloride;

TEMPO 2,2,6,6-tetramethyl-1-piperidinyloxy

THF tetrahydrofuran.

Starting materials used were either available from commercial sources orprepared according to literature procedures and had experimental data inaccordance with those reported. The following is an example of astarting material that was prepared: 3-Amino-1H-pyrrole-2-carboxylicacid ester: Furneaux, R. H., Tyler, P. C., J. Org. Chem. 1999, 64,8411-8412.

General Method A

A reaction mixture of the amino pyrrole ester A1 (1.0 equiv.), thealdehyde A2 (1.0 to 2.0 equiv.) and NaCNBH₃ (1.0 equiv.) in methanol wasstirred at r.t. for 24 h. In some examples, acetic acid (1 to 2 equiv.)was added to catalyze the reaction. If the reaction was not completeafter 24 h (monitored by TLC or LC-MS), more aldehyde A2 was added andthe mixture was stirred at r.t. until the reaction was complete. Themixture was then evaporated onto silica gel and purified by flash columnchromatography.

General Method B

Ethoxycarbonyl isothiocyanate B2 (1.0 to 1.2 equiv.) was added to theamino pyrrole ester B1 (1.0 equiv.) in CH₂Cl₂ and the mixture wasstirred at r.t. for 5 to 60 minutes, or overnight. Water was added andthe aqueous phase was extracted with CH₂Cl₂. The organic phase wascombined, dried (MgSO₄) and concentrated. The crude ring openedintermediate was purified by flash column chromatography. Theintermediate product was dissolved in 1M NaOEt in EtOH (1.1-1.5 equiv.)and heated in a microwave reactor for 10 minutes at 120° C. The pH wasadjusted to neutral pH with 2M HCl; the solid was collected byfiltration and washed with water. The crude product was purified usingpreparative HPLC, or by flash column chromatography or byrecrystallization.

The invention is illustrated, but in no way limited, by the followingexamples. Except where otherwise indicated, the compounds of Examples 1ato 4a and 5c and 7b were prepared using the procedure of General MethodA, and the compounds of Examples 1b to 4b and 5d and 7c were preparedusing the procedure of General Method B.

EXAMPLE 11-Butyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one (a)3-(Butylamino)-1H-pyrrole-2-carboxylic acid ethyl ester

The title compound was obtained as an oil in 60% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.81 g, 5.26 mmol) andbutyraldehyde (0.47+0.55 mL, 11.4 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.71 (1H, br s), 6.74 (1H, t, J=3.1 Hz), 5.62(1H, t, J=2.6 Hz) 5.19 (1H, s), 4.17 (2H, q, J=7.0 Hz), 3.04 (2H, q,J=6.6 Hz), 1.50 (2H, m), 1.34 (2H, m), 1.25 (3H, t, J=7.0 Hz), 0.90 (3H,t, J=7.3 Hz);

MS (ESI) m/z 211 (M+1).

(b) 1-Butyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 44% yield starting from3-(butylamino)-1H-pyrrole-2-carboxylic acid ethyl ester (0.10 g, 0.48mmol) and ethoxycarbonyl isothiocyanate (0.06 mL, 0.58 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.38 (1H, s), 12.10 (1H, s), 7.37 (1H, d,J=2.9), 6.31 (1H, d, J=2.6 Hz), 4.36 (2H, m), 1.69 (2H, m), 1.38 (2H,m), 0.92 (3H, t, J=7.5 Hz);

MS (ESI) m/z 224 (M+1).

EXAMPLE 21-Isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one (a)3-(Isobutylamino)-1H-pyrrole-2-carboxylic acid ethyl ester

The title compound was obtained as an oil in 71% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.40 g, 2.59 mmol) andisobutyraldehyde (0.26+0.07 mL, 3.61 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.68 (1H, s), 6.74 (1H, t, J=3.0 Hz), 5.62 (1H,t, J=2.4 Hz), 5.30 (1H, br s), 4.18 (2H, q, J=7.2 Hz), 2.88 (2H, t,J=6.4 Hz), 1.79 (1H, m), 1.26 (3H, t, J=7.1 Hz), 0.90 (3H, s), 0.89 (3H,s);

¹³C NMR (DMSO-d₆) δ ppm 160.9, 124.2, 95.0, 58.2, 52.4, 27.9, 20.0,14.7;

MS (ESI) m/z 211 (M+1).

(b) 1-Isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 24% yield starting from3-(isobutylamino)-1H-pyrrole-2-carboxylic acid ethyl ester (0.38 g, 1.79mmol) and ethoxycarbonyl isothiocyanate (0.24 mL, 2.15 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.36 (1H, br s), 12.13 (1H, br s), 7.35 (1H, d,J=2.8 Hz), 6.34 (1H, d, J=2.8 Hz), 4.21 (2H, d, =7.33 Hz), 2.44 (1H, m),0.91 (3H, s), 0.90 (3H, s);

¹³C NMR (DMSO-d₆) δ ppm 172.8, 152.4, 137.3, 127.7, 113.6, 97.1, 56.2,26.4, 19.7;

MS (ESI) m/z 224 (M+1).

EXAMPLE 31-(Pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-[(Pyridin-2-ylmethyl)amino]-1H-pyrrole-2-carboxylic acid ethylester

The title compound was obtained as an oil in 54% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.40 g, 2.59 mmol) and2-pyridinecarboxaldehyde (0.27+0.07 mL, 3.55 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.77 (1H, br s), 8.52 (1H, d, J=4.0 Hz),7.80-7.67 (1H, m), 7.35 (1H, d, J=7.8 Hz), 7.25 (1H, dd, J=7.3, 5.0 Hz),6.71 (1H, t, J=3.0 Hz), 6.10 (1H, br s), 5.57 (1H, t, J=2.4 Hz), 4.37(2H, d, J=5.8 Hz), 4.21 (2H, q, J=7.2 Hz), 1.29 (3H, t, J=7.1 Hz);

MS (ESI) m/z 246 (M+1).

(b)1-(Pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 14% yield starting from3-[(pyridin-2-ylmethyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester(0.34 g, 1.39 mmol) and ethoxycarbonyl isothiocyanate (0.19 mL, 1.66mmol).

¹H NMR (DMSO-d₆) δ ppm 12.34 (2H, br s), 8.49 (1H, d, J=4.5 Hz), 7.73(1H, m), 7.29 (1H, d, J=2.8 Hz), 7.27 (1H, m), 7.21 (1H, d, J=7.8 Hz),6.09 (1H, d, J=2.8 Hz), 5.75 (2H, s);

¹³C NMR (DMSO-d₆) δ ppm 173.4, 155.2, 152.6, 149.1, 137.1, 136.8, 127.9,122.4, 121.2, 113.6, 96.9, 54.2;

MS (ESI) m/z 259 (M+1).

EXAMPLE 41-(2-Fluoro-benzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-(2-Fluoro-benzylamino)-1H-pyrrole-2-carboxylic acid ethyl ester

The title compound was obtained as an oil in quantitative yield startingfrom 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.50 g, 3.2mmol), and 2-fluorobenzaldehyde (0.34 mL, 3.2 mmol) using the generalprocedure A but with the following modifications. After 5 h more NaCNBH₃(100 mg, 1.6 mmol) was added followed by more 2-fluorobenzaldehyde (120mg, 1 mmol), and the reaction was then stirred overnight.

¹H NMR (DMSO-d₆) δ ppm 10.76 (1H, br s), 7.47 (1H, m), 7.38 (1H, m),7.28 (2H, m), 6.70 (1H, m), 5.74 (1H, br s), 5.61 (1H, m), 4.34 (2H, m),4.18 (2H, q, J=7.1 Hz), 1.25 (3H, t, J=7.1 Hz);

MS (ES) m/z 263 (M+1).

(b)1-(2-Fluoro-benzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 45% yield starting from3-(2-fluoro-benzylamino)-1H-pyrrole-2-carboxylic acid ethyl ester (0.85g, 3.2 mmol) and ethoxycarbonyl isothiocyanate (0.44 mL, 3.9 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.41 (2H, br s.), 7.33 (2H, m), 7.24 (1H, m),7.10 (1H, m, J=7.5, 7.5 Hz), 7.01 (1H, m, J=7.1 Hz, 7.1 Hz), 6.12 (1H,d, J=2.8 Hz), 5.72 (2H, s);

¹³C NMR (DMSO-d₆) δ 173.9, 161.4, 159.0, 152.9, 137.1, 129.6, 129.5,128.5, 128.1, 128.1, 125.0, 124.9, 123.2, 123.0, 115.8, 115.6, 114.1,96.9, 47.1, 47.1;

MS (ESI) m/z 276 (M+1).

EXAMPLE 51-[2-(2-Methoxyethoxy)-3-propoxybenzyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-Hydroxy-2-(2-methoxyethoxyl)benzaldehyde

2-Chloroethyl methyl ether (4.63 mL, 50.7 mmol) was added dropwise to amixture of 2,3-dihydroxybenzaldehyde (7.0 g, 50.7 mmol), potassiumiodide (8.41 g, 50.69 mmol) and potassium carbonate (7.71 g, 55.8 mmol)in DMF (80 mL). The resulting mixture was stirred at r.t. under anitrogen atmosphere for two days and at 70° C. for two days. Thereaction mixture was partitioned between saturated ammonium chloride(aq.) and CH₂Cl₂. The water phase was re-extracted with CH₂Cl₂ and thecombined organic phases were washed with brine, dried (Na₂SO₄) andevaporated onto silica. Purification by flash column chromatography(heptane/ethyl acetate gradient; 0 to 30% ethyl acetate) yielded a crudeoil which was further purified by flash column chromatography(heptane/ethyl acetate gradient; 0 to 40% ethyl acetate) to yield thetitle compound (3.13 g, 31%) as an oil.

¹H NMR (DMSO-d₆) δ ppm 10.34 (1H, br s), 9.88 (1H, br s), 7.16 (2H, m),7.05 (1H, m), 4.25 (2H, m), 3.60 (2H, m), 3.26 (3H, m);

¹³C NMR (DMSO-d₆) δ ppm 190.5, 150.7, 149.6, 129.9, 124.1, 122.6, 116.9,72.1, 70.9, 57.9;

MS (ESI) m/z 197 (M+1).

(b) 2-(2-Methoxyethoxy)-3-propoxybenzaldehyde

1-Iodopropane (3.09 mL, 31.60 mmol) was added to a solution of3-hydroxy-2-(2-methoxyethoxyl)benzaldehyde (3.1 g, 15.8 mmol) andpotassium carbonate (4.37 g, 31.60 mmol) in DMF (80 mL) and the mixturewas stirred at 100° C. overnight under a nitrogen atmosphere. Thereaction mixture was partitioned between saturated ammonium chloride(aq.) and CH₂Cl₂. The organic phase was washed with brine, dried(Na₂SO₄) and concentrated to give the title compound in quantitativeyield (3.8 g) as an oil. This material was used in the next step withoutfurther purification.

¹H NMR (DMSO-d₆) δ ppm 10.37 (1H, s), 7.36 (1H, m, J=8.0 Hz), 7.26 (1H,m), 7.17 (1H, t, J=7.8 Hz), 4.28 (2H, m), 4.02 (2H, t, J=6.3 Hz), 3.62(2H, m), 3.26 (3H, s), 1.80 (2H, m), 1.02 (3H, t, J=7.3 Hz);

¹³C NMR (DMSO-d₆) δ ppm 190.3, 152.1, 150.9, 129.6, 124.4, 119.4, 117.8,72.5, 70.9, 70.0, 57.9, 22.1, 10.4;

MS (ESI) m/z 239 (M+1).

(c)3-{[2-(2-Methoxyethoxy)-3-propoxybenzyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester

The title compound was obtained as an oil in quantitative yield startingfrom 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.35 g, 2.27mmol) and 2-(2-methoxyethoxy)-3-propoxybenzaldehyde (0.47+0.08 g, 3.06mmol).

¹H NMR (DMSO-d₆) δ ppm 10.69 (1H, br s), 7.13 (1H, s), 7.6.99 (2H, m),6.70 (1H, m), 5.63 (1H, m), 4.92 (1H, t, J=5.7 Hz), 4.52 (2H, d, J=5.8Hz), 4.19 (2H, m), 4.05 (2H, m), 3.92 (2H, t, J=6.4 Hz), 3.59 (2H, m),3.32 (3H, s), 1.76 (2H, m), 1.26 (3H, t, J=7.1 Hz), 1.00 (3H, m);

MS (ESI) m/z 377 (M+1).

(d)1-[2-(2-Methoxyethoxy)-3-propoxybenzyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 13% yield starting from3-{[2-(2-methoxyethoxy)-3-propoxybenzyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester (0.87 g, 2.31 mmol) and ethoxycarbonyl isothiocyanate(0.26 mL, 2.31 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.43 (1H, br s), 12.31 (1H, br s), 7.29 (1H, d,J=3.0 Hz), 6.96-6.85 (2H, m), 6.41 (1H, dd, J=7.3, 1.5 Hz), 6.02 (1H, d,J=2.8 Hz), 5.71 (2H, s), 4.23 (2H, m), 3.95 (2H, t, J=6.3 Hz), 3.65 (2H,m), 3.33 (3H, s), 1.82-1.72 (2H, m), 1.02 (3H, t, J=7.4 Hz);

MS (ESI) m/z 390 (M+1).

EXAMPLE 61-(6-Ethoxy-pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 6-Ethoxy-pyridine-2-carboxylic acid ethyl ester

Ethyl iodide (2.3 mL, 28.8 mmol) was added to a suspension of6-hydroxy-pyridine-2-carboxylic acid (1.0 g, 7.2 mmol) and silver(I)carbonate (4.0 g, 14.4 mmol) in CHCl₃ (70 mL). The suspension wasstirred at ambient temperature for 3 days. Insoluble material wasremoved by filtration and the solid was washed with CHCl₃. The filtratewas concentrated to give the title product in quantitative yield (1.5 g)as an oil. This material was used in the next step without furtherpurification.

¹H NMR (CDCl₃) δ ppm 7.65 (2H, m), 6.88 (1H, m), 4.45 (2H, q, J=7.0 Hz),4.41 (2H, q, J=7.3 Hz), 1.40 (6H, m);

MS (ESI) m/z 196 (M+1).

(b) (6-Ethoxy-pyridin-2-yl)-methanol

NaBH₄ (5.7 g, 151 mmol) was added in portions during 35 minutes to6-ethoxy-pyridine-2-carboxylic acid ethyl ester (1.5 g, 7.5 mmol) inEtOH (75 mL). The resulting mixture was stirred at ambient temperaturefor two days. Water was added and the mixture was extracted with CH₂Cl₂.The organic phase was dried (Na₂SO₄), filtered and then concentrated togive the title product (0.85 g) in 74% yield as an oil. This materialwas used in the next step without further purification.

¹H NMR (CDCl₃) δ ppm 7.55 (1H, m), 6.77 (1H, d, J=7.4 Hz), 6.61 (1H, d,J=8.1 Hz), 4.66 (2H, d, J=5.3 Hz), 4.38 (2H, q, J=7.1 Hz), 3.46 (1H, t,J=5.2 Hz), 1.41 (3H, t, J=7.1 Hz).

(c) 6-Ethoxy-pyridine-2-carbaldehyde

DMSO (0.50 mL, 6.4 mmol) in CH₂Cl₂ (10 mL) was added dropwise to asolution of oxalyl chloride (2M in CH₂Cl₂, 3.1 mL, 6.1 mmol) in CH₂Cl₂(20 mL) at −60° C. The resulting mixture was stirred at −60° C. for 10minutes. (6-Ethoxy-pyridin-2-yl)-methanol (0.85 g, 5.6 mmol) in CH₂Cl₂(5 mL) and DMSO (4 mL) was added dropwise. The mixture was stirred at−60° C. for 3 h, and was then allowed to warm to −20° C. and Et₃N (6 mL)was added. The resulting solution was stirred at ambient temperature for40 minutes. Water was added and the mixture was extracted with CH₂Cl₂.The organic phase was washed with brine, dried (Na₂SO₄), andconcentrated. Diethyl ether was added to the residue and insolublematerial was removed by filtration. The filtrate was concentrated toyield the title compound (0.60 g) in 70% yield as a solid. This crudeproduct was used in the next step without further purification.

¹H NMR (CDCl₃) δ ppm 9.93 (1H, s), 7.71 (1H, m), 7.53 (1H, d, J=7.1 Hz),6.94 (1H, d, J=8.3 Hz), 4.46 (2H, d, J=7.1 Hz), 1.42 (3H, t, J=7.1 Hz).

(d) 3-[(6-Ethoxy-pyridin-2-ylmethyl)-amino]-1H-pyrrole-2-carboxylic acidethyl ester

Acetic acid (0.3 mL) was added to 6-ethoxy-pyridine-2-carbaldehyde (0.59g, 3.9 mmol) and 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.30g, 1.9 mmol) in ethanol (10 mL). After 1.5 h, NaCNBH₃ (0.24 g, 3.9 mmol)was added, and the resulting mixture was stirred at ambient temperaturefor 19 h. The solvent was removed in vacuo, ethyl acetate was added tothe residue, and insoluble material was removed by filtration. Thefiltrate was concentrated and the crude product was purified by flashcolumn chromatography (heptane/ethyl acetate gradient; 0 to 35% ethylacetate), obtaining 0.25 g (45%) of the title product as a solid.

¹H NMR (CDCl₃) δ ppm 8.16 (1H, br s), 7.50 (1H, m), 6.89 (1H, d, J=7.3Hz), 6.70 (1H, br s), 6.57 (1H, d, J=8.1 Hz), 4.45 (2H, q, J=7.0 Hz),5.71 (1H, m), 4.38 (5H, m), 1.37 (6H, m);

MS (ESI) m/z 290 (M+1).

(e)1-(6-Ethoxy-pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Ethoxycarbonyl isothiocyanate (0.12 g, 0.90 mmol) was added to3-[(6-ethoxy-pyridin-2-ylmethyl)-amino]-1H-pyrrole-2-carboxylic acidethyl ester (0.24 g, 0.82 mmol) in CH₂Cl₂ (5 mL) and the solution wasstirred at ambient temperature for 35 minutes. The solvent wasevaporated and 0.4M NaOEt in ethanol (3 mL, 1.2 mmol) was added to theresidue and the mixture was refluxed for 1 h. More NaOEt (0.4M inethanol, 1.5 mL, 0.6 mmol) was added and the solution was refluxed foranother 1.5 h. The solvent was evaporated, the residue was dissolved inwater and the pH adjusted to neutral pH with 1M HCl. The resulting solidwas collected, washed, and dried to give crude product. This materialwas purified by preparative HPLC to yield the title compound (38 mg,15%) as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.32 (2H, br s), 7.62 (1H, m), 7.29 (1H, d,J=3.0 Hz), 6.78 (1H, d, J=7.3 Hz), 6.64 (1H, d, J=8.3 Hz), 6.13 (1H, d,J=2.8 Hz), 5.65 (2H, s), 4.17 (2H, q, J=7.1 Hz), 1.19 (3H, 7, J=7.0 Hz);

¹³C NMR (DMSO-d₆) δ 173.5, 162.7, 152.8, 152.5, 139.6, 137.2, 127.8,113.9, 113.6, 109.0, 97.0, 61.0, 53.8, 14.3;

MS (ESI) m/z 303 (M+1).

EXAMPLE 71-Piperidin-3-ylmethyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-Formyl-piperidine-1-carboxylic acid tert-butyl ester

DMSO (0.18 mL, 2.6 mmol) in CH₂Cl₂ (5 mL) was added dropwise to asolution of oxalyl chloride (2M in CH₂Cl₂, 0.65 mL, 1.3 mmol) in CH₂Cl₂(4 mL) at −78° C. The resulting mixture was stirred at −68° C. for 15minutes. 3-Hydroxymethyl-piperidine-1-carboxylic acid tert-butyl ester(Dean A. Wacker et al. Bioorganic & Medicinal Chemistry Letters 2002,12, 1785-1789) (0.22 g, 1.0 mmol) in CH₂Cl₂ (4 mL) was added dropwiseand after 15 min stirring at −78° C., Et₃N (6 mL) was added. Theresulting solution was stirred at ambient temperature for 16 h. Waterwas added and the mixture was extracted with diethyl ether, the organiclayer was dried (Na₂SO₄) and concentrated to give the product as anyellow oil (0.20 g, 92% yield). This crude product was used in the nextstep without further purification.

MS (ESI) m/z 214 (M+1).

(b)3-[(2-Ethoxycarbonyl-1H-pyrrol-3-ylamino)-methyl]-piperidine-1-carboxylicacid tert-butyl ester

The title compound was obtained as an oil in 30% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.14 g, 0.92 mmol) and3-formyl-piperidine-1-carboxylic acid tert-butyl ester (0.20 g, 0.92mmol).

¹H NMR (CDCl₃) δ ppm 8.29 (1H, br s), 6.70 (1H, s), 5.67 (1H, m), 4.27(2H, m), 3.93 (1H, br s), 3.85 (1H, d, J=13.2 Hz), 3.10-2.94 (2H, m),2.83 (1H, m), 2.65 (1H, br s), 1.85 (1H, m), 1.76 (1H, m), 1.64 (1H, m),1.42 (9H, s), 1.31 (3H, t, J=6.8 Hz), 1.22 (1H, m);

MS (ESI) m/z 352 (M+1).

(c)1-Piperidin-3-ylmethyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 20% yield using3-[(2-ethoxycarbonyl-1H-pyrrol-3-ylamino)-methyl]-piperidine-1-carboxylicacid tert-butyl ester (97 mg, 0.27 mmol) and ethoxycarbonylisothiocyanate (36 mg, 0.27 mmol) using the general procedure B, withthe following modifications. After the base mediated cyclizationreaction, 6M HCl (0.3 mL) was added to the reaction followed by heatingin a microwave reactor for 4 minutes at 100° C. The solvent was removedin vacuo and the residual solid was purified by preparative HPLC usingAtlantis C18 19×100 mm, 5 μm column. Gradient with acetonitrile/0.1 Mammonium acetate in 5% acetonitrile in MilliQ Water, run from 0% to 50%acetonitrile, in 15 min. Flow rate: 15 ml/min.

¹H NMR (Methanol-d₄) δ ppm 7.23 (1H, d, J=3.2 Hz), 6.21 (1H, d, J=3.2Hz), 4.46 (1H, m), 4.23 (1H, m), 3.22 (2H, m), 2.86 (2H, m), 2.58 (1H,m), 1.83 (2H, m), 1.62 (1H, m), 1.42 (1H, m);

¹³C NMR (Methanol-d₄) δ 178.8, 154.7, 139.3, 129.5, 115.3, 97.8, 53.7,48.0, 45.2, 34.5, 27.6, 23.2;

MS (ESI) m/z 265 (M+1).

EXAMPLE 81-Butyl-4-thioxo-1,3,4,5-tetrahydro-2H-pyrrolo[3,2-d]pyrimidin-2-one

Ethoxycarbonyl isothiocyanate (0.13 ml, 1.1 mmol) was added to3-(butylamino)-1H-pyrrole-2-carboxylic acid ethyl ester (0.23 g, 1.1mmol) in toluene (5 mL) and the mixture was heated at 90° C. for 1 h.The precipitate was filtered off and washed with hexane. Theintermediate product was treated with potassium hydroxide (0.55 g, 9.9mmol) in water (9 mL), and heated to reflux for 15 h. After cooling toambient temperature, the pH was adjusted to pH 5 with 12 M HCl. Theresultant precipitate was collected by filtration and washed with water.The crude product was purified using preparative HPLC to give the titlecompound (16 mg, 6%) as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.04 (1H, br s), 11.95 (1H, br s), 7.40 (1H, s),6.23 (1H, d, J=2.7 Hz), 3.84 (2H, t, J=7.2 Hz), 1.66-1.56 (2H, m), 1.32(2H, m), 0.89 (3H, t, J=7.3 Hz);

MS (ESI) m/z 224 (M+1).

EXAMPLE 91-(2-Isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3[(2-Isopropoxyethyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester

Trichlorocyanuric acid (1.84 g, 7.93 mmol) was added to a solution of2-isopropoxyethanol (0.75 g, 7.21 mmol) in CH₂Cl₂ (3 mL). The reactionmixture was cooled to 0° C. and TEMPO (0.022 g, 0.14 mmol) was carefullyadded in small portions. The mixture was stirred at r.t. for 20 minutesthen filtered through Celite and washed with CH₂Cl₂. The filtrate waskept cold, 0° C., during filtration. The aldehyde solution was added toa stirred mixture of 3-amino-1H-pyrrole-2-carboxylic acid ester (0.83 g,5.41 mmol) and HOAc (0.62 mL, 10.8 mmol) at 0° C. in methanol (5 mL).The mixture was stirred for 20 minutes, then NaCNBH₃ (0.34 g, 5.41 mmol)was added. After stirring at r.t for 2 h, the solution was evaporatedonto silica and purified by flash column chromatography (heptane/ethylacetate gradient; 0 to 100% ethyl acetate) to yield the title compound(0.75 g, 58%) as an oil.

¹H NMR (DMSO-d₆) δ ppm 10.72 (1H, br s), 6.76-6.74 (1H, m), 5.66-5.65(1H, m), 5.34 (1H, br s), 4.17 (2H, q, J=7.0 Hz), 3.59-3.49 (3H, m),3.15 (2H, q, J=5.6 Hz), 1.26 (3H, t, J=7.0 Hz), 1.10 (3H, s), 1.08 (3H,s);

MS (ESI) m/z 241 (M+1).

(b)1-(2-Isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound (0.17 g, 23%) was prepared in accordance with thegeneral method B using3-[(2-isopropoxyethyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester(0.7 g, 2.91 mmol) and ethoxycarbonyl isothiocyanate (0.40 mL, 3.50mmol).

¹H NMR (DMSO-d₆) δ ppm 12.74 (2H, br s), 7.35 (1H, d, J=2.8 Hz), 6.29(1H, d, J=3.0 Hz), 4.49 (2H, t, J=6.3 Hz), 3.72 (2H, t, J=6.3 Hz),3.60-3.58 (1H, m), 1.02 (3H, s), 1.01 (3H, s);

MS (ESI) m/z 254 (M+1).

EXAMPLE 101-(2-Methoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-[(2-Methoxy-2-methylpropyl)amino]-1H-pyrrole-2-carboxylic acidester

The title compound was obtained as an oil in 75% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.250 g, 1.62 mmol)and 2-methoxy-2-methylpropanal (U.S. Pat. No. 3,652,579) (0.331 g, 3.24mmol) using the general procedure A but with the followingmodifications. After 6 h more 2-methoxy-2-methylpropanal (0.165 g, 1.62mmol) was added, and the reaction mixture was then stirred overnight.

¹H NMR (DMSO-d₆) δ ppm 10.69 (1H, br s), 6.74 (1H, t, J=3.0 Hz), 5.64(1H, t, J=2.6 Hz), 5.33 (1H, br s), 4.17 (2H, q, J=7.1 Hz), 3.11 (3H,s), 3.03 (2H, d, J=5.8 Hz), 1.26 (3H, t, J=7.1 Hz), 1.13 (6H, s);

MS (ESI) m/z 241 (M+1).

(b)1-(2-Methoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 3% yield starting from3-[(2-ethoxy-2-methylpropyl)amino]-1H-pyrrole-2-carboxylic acid ethylester (0.283 g, 1.18 mmol) and ethoxycarbonyl isothiocyanate (0.13 mL,1.18 mmol) using the general procedure B but with the followingmodification. The reaction was run in a microwave reactor for a total of35 minutes.

¹H NMR (DMSO-d₆) δ ppm 12.29 (1H, br s), 12.17 (1H, br s), 7.30 (1H, d,J=2.76), 6.29 (1H, d, J=2.76), 4.58 (2H, br s), 3.12 (3H, s), 1.21 (6H,s);

MS (ESI) m/z 254 (M+1).

EXAMPLE 111-(2-Ethoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 2-Bromo-1,1-diethoxy-2-methylpropane

The product was synthesized according to a modified procedure describedin U.S. Pat. No. 3,652,579. Bromine water (2.95 mL, 57.6 mmol) was addeddropwise to isobutyraldehyde (4.82 g, 66.8 mmol) in ethanol (22 mL) andthe resulting mixture was stirred at r.t. for 40 minutes. More brominewater (0.3 mL, 5.86 mmol) was added. The reaction mixture wasneutralized by addition of calcium carbonate (3.5 g, 25.3 mmol). Theremaining calcium carbonate was filtered off and the filtrate was pouredonto an ice-water mixture. The aqueous phase was extracted with CH₂Cl₂,dried (Na₂SO₄), filtered and concentrated. After vacuum distillation,the title product (10.10 g, 67%) was obtained.

¹H NMR ((DMSO-d₆) δ ppm 4.43 (1H, s), 3.80-3.73 (2H, m), 1.64 (6H, s),1.15 (6H, t, J=7.1 Hz).

(b) 2-Ethoxy-2-methylpropanal

The product was synthesized according to a procedure described in U.S.Pat. No. 3,652,579. 2-Ethoxy-2-methylpropanal (5.63 g, 25 mmol) wasadded dropwise to potassium bitartrate (2.35 g, 12.5 mmol) in refluxingdeionized water (22.5 mL) over 50 minutes. The resulting mixture wasrefluxed for 70 minutes. The solvent and product were distilled offAmmonium sulfate (total 8.5 g) was added to the product-solvent mixture.The mixture was stirred and then the two phases were separated and theupper phase was distilled from calcium chloride obtaining the titleproduct (1.60 g, 55%).

MS (CI) m/z 117 (M+1).

(c) 3-[(2-Ethoxy-2-methylpropyl)amino]-1H-pyrrole-2-carboxylic acidethyl ester

The title compound was obtained as an oil in 63% yield starting from3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.200 g, 1.30 mmol)and 2-ethoxy-2-methyl propionaldehyde (0.292 g, 2.86 mmol) using thegeneral procedure A but with the following modification. The reactionmixture was stirred at r.t. for 48 h.

¹H NMR (CDCl₃) δ ppm 6.74 (1H, br s), 5.70 (1H, br s), 4.32 (2H, q,J=7.4 Hz), 3.54-3.47 (2H, m), 3.44 (2H, q, J=7.6 Hz), 3.12 (2H, d, J=4Hz), 1.25 (6H, s), 1.20 (3H, t, J=7.4 Hz), 1.19 (3H, t, J=7.6 Hz);

MS (ESI) m/z 255 (M+1).

(d)1-(2-Ethoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

3-(2-Methoxy-2-methyl)-propylamino-1H-pyrrole-2 carboxylic acid ethylester (0.200 g, 0.79 mmol) was dissolved in CH₂Cl₂ (2 mL) at r.t. undera nitrogen atmosphere. Ethoxycarbonyl isothiocyanate (0.12 mL, 1.02mmol) was added dropwise and the reaction mixture was stirred at r.t.overnight. The solvent was evaporated and sodium ethoxide (1M inethanol, 0.94 mL, 0.94 mmol) was added and the reaction was heated to40° C. for 48 h. Water (2 mL) was added and the pH was adjusted toneutral pH with 2M HCl. The precipitate was collected by filtration andwas purified by preparative HPLC to give the title compound in 6% yield(0.12 g).

¹H NMR (DMSO-d₆) δ ppm 12.22 (1H, br s), 7.30 (1H, d, J=2.8 Hz), 6.35(1H, d, J=3 Hz), 4.60 (2H, br s), 3.40-3.34 (3H, m), 1.22 (6H, s), 1.04(3H, t, J=7.0 Hz);

MS (ESI) m/z 267 (M+1).

EXAMPLE 121-(Piperidin-4-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a)4-[(2-(Ethoxycarbonyl)-1H-pyrrol-3-ylamino)-methyl]piperidine-1-carboxylicacid tert-butyl ester

The title compound (0.156 g, 10%) was prepared in accordance withgeneral method A starting from 3-amino-1H-pyrrole-2-carboxylic acidethyl ester (0.68 g, 4.4 mmol) and 4-formylpiperidine-1-carboxylic acidtert-butyl ester (P. C. Ting et al., Bioorganic & Medicinal ChemistryLetters, 2001, 11, 491-494) (0.98 g, 4.6 mmol.

¹H NMR (DMSO-d₆) δ ppm 10.70 (1H, br s), 6.74 (1H, br s), 5.65 (1H, brs), 4.19 (2H, q, J=7.2 Hz), 3.95 (2H, d, J=12.0 Hz), 2.97 (2H, t, J=6.0Hz), 2.65 (2H, br s), 1.66 (2H, d, J=12.0 Hz), 1.39 (9H, s), 1.26 (3H,t, J=7.2 Hz), 1.07-0.95 (2H, m);

MS (ESI) m/z 352 (M+1).

(b)1-(Piperidin-4-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Ethoxycarbonyl isothiocyanate (0.058 g, 0.44 mmol) was added to astirred solution of4-[(2-(ethoxycarbonyl)-1H-pyrrol-3-ylamino)-methyl]piperidine-1-carboxylicacid tert-butyl ester (0.156 g, 0.44 mmol) in CH₂Cl₂ (2 mL) and themixture was stirred at r.t. for 1 h. The solvent was removed in vacuoand the residue was taken up in ethanol (1 mL) containing sodium (0.015g, 0.66 mmol). The resulting mixture was heated in a microwave reactorat 120° C. for 10 minutes. 6M HCl (0.5 mL) was added and the reactionmixture was heated again in the microwave at 100° C. for 3 minutes. ThepH was adjusted to neutral pH with 2M HCl and the solution wasconcentrated in vacuo. The crude product was purified by preparativeHPLC to give the title compound (0.038 g, 14%) as a white solid.

¹H NMR (DMSO-d₆) δ ppm 7.36 (1H, d, J=2.8 Hz), 6.33 (1H, d, J=2.8 Hz),4.27 (2H, br s), 2.95 (2H, d, J=12.0 Hz), 2.40 (2H, t, J=10.4 Hz),2.25-2.15 (1H, m), 1.50 (2H, d, J=10.8 Hz), 1.37-1.20 (2H, m);

¹³C NMR (DMSO-d₆) δ ppm 173.2, 152.9, 137.6, 128.1, 114.0, 97.5, 55.2,45.5, 34.7, 30.0;

MS (ESI) m/z 265 (M+1).

EXAMPLE 131-[(1-Methylpiperidin-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

1-Piperidin-3-ylmethyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(Example 7) (0.092 g, 0.35 mmol) was dissolved in methanol (2 mL) andformic acid (37% aq., 0.059 mL, 0.7 mmol) was added. After 5 minutes ofstirring at r.t. a precipitate had formed. NaCNBH₃ (0.026 g, 0.42 mmol)was added and the mixture was stirred at r.t. for 1 h. The solvent wasremoved in vacuo and the residual solid was purified by preparativeHPLC, obtaining the title compound (0.022 g, 22%) as a white solid.

¹H NMR (DMSO-d₆) δ ppm 12.22 (1H, br s), 7.36 (1H, d, J=2.8 Hz), 6.33(1H, s), 4.27 (2H, br s), 2.61-2.5 (1H, m), 2.36-2.30 (1H, m), 2.09 (3H,s), 1.93-1.82 (3H, m), 1.65-1.52 (2H, m), 1.44-1.32 (1H, m), 1.16-1.07(1H, m);

¹³C NMR (DMSO-d₆) δ ppm 173.2, 152.9, 137.6, 128.1, 114.0, 97.3, 59.2,56.0, 53.3, 46.7, 34.9, 27.7, 24.7;

MS (ESI) m/z 279 (M+1).

EXAMPLE 141-[2-Hydroxy-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Methyl {[tert-butyl(dimethyl)silyl]oxy}(4-methoxyphenyl)acetate

TBDMSCl (1.5 g, 9.94 mmol) and imidazole (1.0 g, 14.6 mmol) were addedto a solution of methyl hydroxy-(4-methoxyphenyl)acetate (TeodozyjKolasa et al., J. Org. Chem., 1987, 22, 4978-4984) (1.3 g, 6.62 mmol) inDMF (8 mL) and the mixture was stirred at r.t. for 2 h. Water was addedand the mixture was extracted with diethyl ether. The organic layer waswashed with brine, dried (MgSO₄), filtered and concentrated to give thetitle compound (2.0 g, 97%).

¹H NMR (CDCl₃) δ ppm 7.39 (2H, d, J=8.8 Hz), 6.88 (2H, d, J=8.8 Hz),5.19 (1H, s), 3.81 (3H, s), 3.69 (3H, s), 0.92 (9H, s), 0.11 (3H, s),0.03 (3H, s).

(b) {[tert-Butyl(dimethyl)silyl]oxy}(4-methoxyphenyl)acetaldehyde

Methyl {[tert-butyl(dimethyl)silyl]oxy}(4-methoxyphenyl)acetate (0.5 g,1.61 mmol) was dissolved in toluene (10 mL) and cooled to −78° C. undera nitrogen atmosphere. DIBAL (1.0M in toluene, 1.9 mL, 1.93 mmol) wasadded slowly and the mixture was stirred at −78° C. for 1 h. Thereaction mixture was poured onto a mixture of ice (20 g) and CHCl₃ (20mL). The mixture was stirred at r.t. for 30 minutes. The layers wereseparated and the water phase extracted with CHCl₃. The organic phasewas washed with brine, dried (MgSO₄), filtered and concentrated,obtaining 99% (0.45 g) of the title compound. The product was useddirectly in the next step without further purification.

¹H NMR (CDCl₃) δ ppm 7.40-7.38 (2H, m), 6.89-6.87 (2H, m), 5.19 (1H, s),3.81 (3H, s), 0.92 (9H, s), 0.11 (3H, s), 0.03 (3H, s).

(c)3-{[2-{[tert-Butyl(dimethyl)silyl]oxy}-2-(4-methoxyphenyl)ethyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester

The title compound (0.13 g, 19%) was prepared in accordance with generalmethod A using 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.16 g,1.07 mmol) and{[tert-butyl(dimethyl)silyl]oxy}(4-methoxyphenyl)acetaldehyde (0.3 g,1.07 mmol).

MS (ESI) m/z 417 (M−1).

(d)1-[2-{[tert-Butyl(dimethyl)silyl]oxy}-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound (0.07 g, 90%) was prepared in accordance with generalmethod B using3-{[2-{[tert-butyl(dimethyl)silyl]oxy}-2-(4-methoxyphenyl)ethyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester (0.13 g, 0.31 mmol) and ethoxycarbonyl isothiocyanate(0.042 mL, 0.37 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.28-12.23 (2H, m), 7.42 (2H, d, J=8.6 Hz),7.34-7.33 (1H, m), 6.96 (2H, d, J=8.6 Hz), 6.33 (1H, br s), 5.53-5.50(1H, m), 4.57 (1H, br s), 4.15 (1H, br s), 3.76 (3H, s), 0.61 (9H, s),0.31 (3H, s), 0.39 (3H, s);

MS (ESI) m/z 432 (M+1).

(e)1-[2-Hydroxy-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Tetra-n-butylammonium fluoride (1M in THF, 1.27 mL, 1.27 mmol) was addedto1-[2-{[tert-butyl(dimethyl)silyl]oxy}-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(0.065 g, 0.152 mmol) in THF (8 mL). The mixture was stirred at 50° C.overnight. Ethyl acetate was added, and the organic phase was washedwith water and brine, dried (MgSO₄), filtered and concentrated. Thiscrude material was purified by preparative HPLC to yield the titlecompound (0.018 g, 37%) as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.20 (2H, br s), 7.40 (2H, d, J=8.5 Hz), 7.29(1H, d, J=2.8 Hz), 6.91 (2H, d, J=8.8 Hz), 6.27 (1H, d, J=2.8 Hz),5.42-5.41 (1H, m), 5.28-5.24 (1H, m), 4.62-4.58 (1H, m), 4.19-4.16 (1H,m), 3.74 (3H, s);

MS (ESI) m/z 316 (M−1).

EXAMPLE 151-(2-Methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-[(2-Methoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester

The title compound was obtained as a white solid in quantitative yieldstarting from 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.350 g,2.27 mmol) and ortho-anisaldehyde (0.37 g, 2.71 mmol) using generalprocedure A but with the following modifications. After stirringovernight, the reaction mixture was evaporated. The crude solid wastaken up in CHCl₃, filtered and the solvent was evaporated in vacuo, andthis crude product was used in the next step without furtherpurification.

MS (ESI) m/z 275 (M+1).

(b)1-(2-Methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 16% yield starting from3-[(2-methoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester(0.622 g, 2.27 mmol) and ethoxycarbonyl isothiocyanate (0.26 mL, 2.27mmol) using general procedure B but with the following modification. Theintermediate crude product was dissolved in 1M NaOEt (2.27 mL, 2.27mmol) and was stirred at 80° C. for 3 h.

¹H NMR (DMSO-d₆) δ ppm 12.36 (2H, br s), 7.27 (1H, d, J=2.8 Hz),7.27-7.21 (1H, m), 7.06 (1H, d, J=8.1 Hz), 6.82 (1H, t, J=7.3 Hz),6.79-6.75 (1H, m), 5.96 (1H, d, J=2.8 Hz), 5.61 (2H, s), 3.89 (3H, s);

MS (ESI) m/z 288 (M+1).

EXAMPLE 161-(3-Methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3[(3-Methoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester

The title compound was obtained as an oil in 57% (0.508 g) yield and wasprepared in accordance with general method A using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.50 g, 3.24 mmol) andm-anisaldehyde (0.47 mL, 3.89 mmol.

¹H NMR (DMSO-d₆) δ ppm 10.73 (1H, br s), 7.24-7.20 (1H, m), 6.90-6.86(1H, m), 6.80-6.77 (1H, m), 6.71-6.69 (1H, m), 5.75 (1H, br s),5.59-5.58 (1H, m), 4.46 (1H, d, J=5.8 Hz), 4.25 (2H, d, J=6.3 Hz), 4.19(2H, q, J=7.1 Hz), 3.72 (3H, s), 1.26 (3H, t, J=7.1 Hz);

MS (ESI) m/z 275 (M+1).

(b)1-(3-Methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 3% (0.014 g) yield and wasprepared in accordance with general method B using3-[(3-methoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester(0.494 g, 1.80 mmol) and ethoxycarbonyl isothiocyanate (0.20 mL, 1.18mmol).

¹H NMR (DMSO-d₆) δ ppm 12.41-12.34 (2H, m), 7.29 (1H, d, J=2.7 Hz), 7.23(1H, t, J=8.0 Hz), 6.93-6.91 (1H, m), 6.86 (1H, d, J=7.8 Hz), 6.83 (1H,dd, J=8.2, 2.4 Hz), 6.14 (1H, d, J=2.8 Hz), 5.67 (2H, s), 3.71 (3H, s);

MS (ESI) m/z 288 (M+1).

EXAMPLE 171-(2,4-Dimethoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-[(2,4-Dimethoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethylester

The title compound was obtained as an oil in 85% (0.838 g) yield and wasprepared in accordance with general method A using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.50 g, 3.24 mmol) and2,4-dimethoxybenzaldehyde (0.647 g, 3.89 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.69 (1H, br s), 7.14 (1H, d, J=8.3 Hz), 6.71(1H, t, J=3.0 Hz), 6.54 (1H, d, J=2.3 Hz), 6.44 (1H, dd, J=8.3 Hz), 5.66(1H, t, J=2.5 Hz), 5.59 (1H, br s), 4.20-4.13 (4H, m), 3.80 (3H, s),3.73 (3H, s), 1.25 (3H, t, J=7.1 Hz);

¹³C NMR (DMSO-d₆) δ ppm 160.9, 159.6, 158.0, 129.2, 124.0, 120.0, 104.2,98.3, 95.5, 58.3, 55.4, 55.1, 43.6, 14.7;

MS (ESI) m/z 303 (M−1).

(b)1-(2,4-Dimethoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 14% (0.118 g) yield andwas prepared in accordance with general method B using3-[(2,4-dimethoxybenzyl)amino]-1H-pyrrole-2-carboxylic acid ethyl ester(0.828 g, 2.72 mmol) and ethoxycarbonyl isothiocyanate (0.31 mL, 2.72mmol).

¹H NMR (DMSO-d₆) δ ppm 12.41 (1H, br s), 12.27 (1H, s), 7.27 (1H, t,J=2.9 Hz), 6.77 (1H, d, J=8.3 Hz), 6.61 (1H, d, J=2.3 Hz), 6.41 (1H, dd,J=8.5, 2.4 Hz), 5.95 (1H, t, J=2.3 Hz), 5.54 (2H, s), 3.88 (3H, s), 3.72(3H, s);

MS (ESI) m/z 318 (M+1).

EXAMPLE 181-[(3-Chloropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-{[(3-chloropyridin-2-yl)methyl]amino}-1H-pyrrole-2-carboxylic acidethyl ester

The title compound was obtained as a solid in 91% (0.225 g) yield andwas prepared in accordance with general method A using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.231 g, 1.50 mmol)and 3-chloropyridine-2-carbaldehyde (Nadeem Iqbal et al., J. Med. Chem.1998, 41, 1827-1837) (0.212 g, 1.50 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.81 (1H, br s), 8.53-8.51 (1H, m), 7.94-7.92(1H, m), 7.40-7.36 (1H, m), 6.77-6.76 (1H, m), 5.74-5.73 (1H, m), 4.43(1H, d, J=5.5 Hz), 4.20-4.15 (2H, m), 1.30-1.27 (3H, m);

MS (ESI) m/z 280 (M+1).

(b)1-[(3-Chloropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 5% (0.011 g) yield and wasprepared in accordance with general method B using3-{[(3-chloropyridin-2-yl)methyl]amino}-1H-pyrrole-2-carboxylic acidethyl ester (0.215 g, 0.77 mmol) and ethoxycarbonyl isothiocyanate (0.09mL, 0.77 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.26 (1H, br s), 8.32-8.30 (1H, m), 7.96-7.93(1H, m), 7.34-7.30 (1H, m), 7.28 (1H, d, J=3.0 Hz), 6.16 (1H, d, J=2.8Hz), 5.80 (2H, s);

MS (ESI) m/z 293 (M+1).

EXAMPLE 191-{[3-(2-Ethoxyethoxyl)pyridin-2-yl]methyl}-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-(2-Ethoxyethoxy)-2-methylpyridine

Potassium carbonate (2.20 g, 15.9 mmol) was added to a stirred solutionof 3-hydroxy-2-methylpyridine (1.45 g, 13.3 mmol) and 2-chloroethylethyl ether (1.75 mL, 15.9 mmol) in DMF (7 mL) and the mixture wasstirred at 70° C. overnight. The reaction was not complete andadditional 2-chloroethyl ethyl ether (1 equiv.) and potassium carbonate(1 equiv.) were added and the mixture was stirred at 85° C. for 8 h.Water and ethyl acetate were added and the aqueous layer was extractedwith ethyl acetate. The organic layer was dried (MgSO₄), filtered andconcentrated. The crude product was purified by flash columnchromatography (heptane/ethyl acetate gradient; 0 to 50% ethyl acetate),obtaining 1.80 g (75%) the title compound.

¹H NMR (DMSO-d₆) δ ppm 8.03-7.99 (1H, m), 7.33-7.31 (1H, m), 7.18-7.14(1H, m), 4.13-4.11 (2H, m), 3.73-3.71 (2H, m), 3.52 (2H, q, J=7.0 Hz),2.35 (3H, s), 1.12 (3H, t, J=6.9 Hz);

MS (ESI) m/z 182 (M+1).

(b) 3-(2-Ethoxyethoxyl)pyridine-2-carbaldehyde

A mixture of 3-(2-ethoxyethoxy)-2-methylpyridine (0.506 g, 2.79 mmol)and selenium dioxide (0.31 g, 2.79 mmol) in 1,4-dioxane (10 mL) washeated at 75° C. overnight. After cooling to r.t., the mixture wasfiltered and the solids were washed with ethyl acetate. The solvent wasremoved in vacuo. The reaction was not complete and the solid wasdissolved in 1,4 dioxane (15 mL) and selenium dioxide (0.31 g, 2.79mmol) was added. The mixture was heated at 110° C. overnight. Ethylacetate (10 mL) was added and the mixture was filtered. The black solidwas washed with ethyl acetate and the filtrate was evaporated in vacuo.The crude product was purified by flash column chromatography(heptane/ethyl acetate gradient; 0 to 100% ethyl acetate), obtaining0.21 g (39%) of the title compound.

¹H NMR (DMSO-d₆) δ ppm 10.23 (1H, s), 8.35 (1H, d, J=4.3 Hz), 7.77 (1H,d, J=8.6 Hz), 7.66-7.62 (1H, m), 4.29 (2H, m), 3.75 (2H, m), 3.55-3.49(2H, m), 1.14-1.09 (3H, m).

(c)3-({[3-(2-Ethoxyethoxyl)pyridin-2-yl]methyl}amino)-1H-pyrrole-2-carboxylicacid ethyl ester

The title compound (0.17 g, 73%) was prepared in accordance with generalmethod A using 3-(2-ethoxyethoxyl)pyridine-2-carbaldehyde (0.21 g, 1.08mmol) and 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.11 g,0.717 mmol).

¹H NMR (DMSO-d₆) δ ppm 10.76 (1H, s), 8.13-8.12 (1H, m), 7.46-7.44 (1H,m), 7.30-7.28 (1H, m), 6.76-6.75 (1H, m), 6.29 (1H, br s), 5.71-5.70(1H, m), 4.32-4.31 (2H, m), 4.22-4.17 (4H, m), 3.77-3.74 (2H, m),3.57-3.51 (2H, m), 1.30 (3H, t, J=7.0 Hz), 1.15-1.12 (3H, m);

MS (ESI) m/z 334 (M+1).

(d)1-{[3-(2-Ethoxyethoxyl)pyridin-2-yl]methyl}-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound (0.051 g, 28%) was prepared in accordance withgeneral method B using3-({[3-(2-ethoxyethoxyl)pyridin-2-yl]methyl}amino)-1H-pyrrole-2-carboxylicacid ethyl ester (0.17 g, 0.52 mmol) and ethoxycarbonyl isothiocyanate(0.07 mL, 0.62 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.32-12.19 (2H, m), 7.92 (1H, d, J=4.0 Hz), 7.47(1H, d, J=7.8 Hz), 7.32-7.14 (2H, m), 5.98 (1H, d, J=2.8 Hz), 5.73 (2H,s), 4.26-4.23 (2H, m), 3.78-3.76 (2H, m), 3.55 (2H, q, J=7.1 Hz), 1.14(3H, t, J=6.9 Hz);

¹³C NMR (DMSO-d₆) δ 173.5, 152.7, 152.4, 143.7, 140.3, 137.8, 127.7,123.0, 119.0, 113.5, 96.8, 68.2, 65.8, 49.8, 15.1;

MS (ESI) m/z 347 (M+1).

EXAMPLE 201-[(6-Oxo-1,6-dihydropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a)3-{[(6-Oxo-1,6-dihydropyridin-2-yl)methyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester

6-Oxo-1,6-dihydropyridine-2-carbaldehyde (WO 2002/006272) (0.31 g, 2.5mmol) was dissolved in EtOH (10 mL). 3-Amino-1H-pyrrole-2-carboxylicacid ethyl ester (0.19 g, 1.3 mmol) was added, followed by HOAc (0.14mL, 2.5 mmol). The mixture was stirred for 75 minutes at r.t. and thenNaCNBH₃ (0.16 g, 2.5 mmol) was added. The reaction mixture was stirredat r.t. overnight. The solvent was evaporated in vacuo and the crudeproduct was purified by flash column chromatography (CH₂Cl₂/methanolgradient; 0 to 10% methanol), obtaining 0.288 g (85%) of the titleproduct as an oil that crystallized upon standing.

¹H NMR (DMSO-d₆) δ ppm 11.57 (1H, br s), 10.77 (1H, br s), 7.34-7.30(1H, m), 6.71-6.70 (1H, m), 6.16-6.13 (2H, m), 5.98 (1H, br s), 5.75(1H, s), 5.64-5.63 (1H, m), 4.20 (2H, q, J=7.1 Hz), 4.09-4.08 (2H, m),1.27 (3H, t, J=7.1 Hz);

MS (ESI) m/z 262 (M+1).

(b)1-[(6-Oxo-1,6-dihydropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Benzoyl isothiocyanate (0.27 g, 1.6 mmol) dissolved in CH₂Cl₂ (3 mL) wasadded to3-{[(6-oxo-1,6-dihydropyridin-2-yl)methyl]amino}-1H-pyrrole-2-carboxylicacid ethyl ester (0.25 g, 0.96 mmol) in CH₂Cl₂ (7 mL). The resultingmixture was stirred at r.t. overnight. The solvent was removed in vacuoand the residue was dissolved in methanol (15 mL) and potassiumcarbonate (0.50 g, 3.6 mmol) was added. The reaction mixture was stirredat 50° C. for 6.5 h. After cooling to r.t., 1M HCl was added dropwiseuntil a neutral pH was obtained.

The resulting precipitate was collected, washed with methanol andpurified by preparative HPLC to obtain the title compound (0.097 g, 37%)as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.46-12.38 (2H, m), 11.69 (1H, br s), 7.34-7.29(2H, m), 6.23 (2H, s), 5.75 (1H, br s), 5.49 (2H, s);

¹³C NMR (DMSO-d₆) δ 173.6, 162.7, 152.5, 140.6, 136.7, 128.0, 113.6,96.6;

MS (ESI) m/z 275 (M+1).

EXAMPLE 211-(1H-indol-3-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Ethyl 3-[(1H-indol-3-ylmethyl)amino]-1H-pyrrole-2-carboxylate

A reaction mixture of 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester(0.075 g, 0.49 mmol), indole-3-carboxaldehyde (0.085 g, 0.58 mmol),NaCNBH₃ (0.031 g, 0.49 mmol) and HOAc (0.056 mL, 0.97 mmol) in methanol(3 mL) was stirred at r.t. overnight. The mixture was concentrated invacuo and the crude product-mixture was used in the next step withoutfurther purification.

MS (ESI) m/z 284 (M+1).

(b)1-(1H-Indol-3-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

A crude mixture of ethyl3-[(1H-indol-3-ylmethyl)amino]-1H-pyrrole-2-carboxylate (max 0.49 mmol)was added to CH₂Cl₂ (5 mL). A few drops of methanol were added toincrease solubility. Benzoylisothiocyanate (0.072 g, 0.53 mmol) wasadded and the mixture was stirred at r.t. for 1 h. The mixture wasconcentrated in vacuo. Ammonia (7N in methanol, 3 mL) was added and themixture was heated at 80° C. for 2 h. The mixture was concentrated andpurified by preparative HPLC, obtaining the title compound (0.030 g,21%) as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.13 (2H, br s), 11.08 (1H, s), 7.87 (1H, d,J=8.1 Hz), 7.54-747 (1H, m), 7.38-7.30 (1H, m), 7.29-7.25 (1H, m),7.10-7.03 (1H, m), 7.01-6.93 (1H, m), 6.33 (1H, d, J=2.8 Hz), 5.88 (2H,s);

¹³C NMR (DMSO-d₆) δ ppm 173.14, 152.86, 136.71, 136.42, 128.02, 126.45,125.83, 121.61, 119.67, 119.16, 114.36, 111.95, 109.51, 97.74, 46.31;

MS (ESI) m/z 295 (M−1).

EXAMPLE 221-(1H-Benzimidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Ethyl 3-[(1H-benzimidazol-2-ylmethyl)amino]-1H-pyrrole-2-carboxylate

A reaction mixture of 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester(0.77 g, 4.99 mmol), 1H-benzoimidazole-2-carboxaldehyde (0.88 g, 5.99mmol), NaCNBH₃ (0.31 g, 4.99 mmol) and HOAc (0.57 mL, 9.99 mmol) inmethanol (15 mL) was stirred at r.t. overnight. The mixture was thenheated at 50° C. for 5 h. Cooled to r.t. and evaporated in vacuo. Theresidue was dissolved in ethyl acetate and washed with water. Theaqueous phase was extracted with ethyl acetate (twice). The combinedorganic layers were dried (MgSO₄) and concentrated. The crude productwas purified by flash column chromatography (heptane/ethyl acetate (1:0to 0:1), obtaining 1.15 g (81%) of the title compound.

¹H NMR (DMSO-d₆) δ ppm 12.27 (1H, s), 10.85 (1H, s), 7.63-7.37 (2H, m),7.17-7.08 (2H, m), 6.71 (1H, t, J=3.0 Hz), 5.99 (1H, br s), 5.60 (1H, t,J=2.7 Hz), 4.48 (2H, d, J=5.8 Hz), 4.22 (2H, q, J=7.1 Hz), 1.29 (3H, t,J=7.1 Hz);

MS (ESI) m/z 285 (M+1).

(b)1-(1H-Benzimidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Ethyl 3-[(1H-benzimidazol-2-ylmethyl)amino]-1H-pyrrole-2-carboxylate(0.33 g, 1.16 mmol) was added to CH₂Cl₂ (3 mL) and methanol was addeduntil clear solution was obtained. The solution was stirred at r.t. for1 h. Benzoyl isothiocyanate (0.73 mL, 0.46 mmol) was added and afterstirring at r.t. for 30 minutes the mixture was concentrated. Theresidue was dissolved in ammonia (7N in methanol, 7 mL) and the mixturewas heated at 80° C. in a sealed steel container for 2 h. After coolingto r.t. the precipitated product was filtrated and washed through withmethanol, diethyl ether and ethyl acetate, obtaining 0.23 g (66%) of thetitle compound as a white solid.

¹H NMR (DMSO-d₆) δ ppm 12.27 (3H, br s), 7.61-7.37 (2H, m), 7.43-7.27(1H, m), 7.18-7.07 (2H, m), 6.19 (1H, d, J=2.8 Hz), 5.89 (2H, s);

MS (ESI) m/z 298 (M+1).

EXAMPLE 231-[(5-Chloro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

5-Chloro-1H-indole-2-carbaldehyde (0.15 g, 0.76 mmol), NaCNBH₃ (0.040 g,0.63 mmol) and Et₃N (0.088 mL, 0.63 mmol) was added to a stirredsolution of 3-amino-1H-pyrrole-2-carboxylic acid ethyl esterhydrochloride (0.12 g, 0.63 mmol) in methanol (3 mL). The resultingmixture was stirred at r.t. overnight. The reaction mixture was heatedto 50° C. Additional NaCNBH₃ (0.5 equiv.) was added and the mixture wasstirred at 50° C. for 3 h. A few drops of HOAc was added, and after 1 hthe reaction mixture was cooled to r.t. and was concentrated in vacuo.The residue was dissolved in CH₂Cl₂ (2 mL) and methanol (2 mL). Benzoylisothiocyanate (0.093 mL, 0.69 mmol) was added and after stirring atr.t. for 1 h the mixture was concentrated in vacuo. The residue wasdissolved in ammonia (7N in methanol, 3 mL) and heated at 80° C. for 2h. The precipitated product was filtered and washed through withmethanol and diethyl ether, followed by purification by preparativeHPLC, obtaining 0.063 g (30%) of the title compound as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.41 (2H, br s), 11.51-11.04 (1H, m), 7.51-7.46(1H, m), 7.40-7.33 (1H, m), 7.33-7.30 (1H, m), 7.07-6.99 (1H, m),6.34-6.27 (2H, m), 5.87-5.80 (2H, m);

¹³C NMR (DMSO-d₆) δ ppm 173.65, 153.05, 136.84, 135.98, 134.74, 129.28,128.27, 123.97, 121.26, 119.19, 114.24, 113.25, 100.33, 97.17, 47.31;

MS (ESI) m/z 331 (M+1).

EXAMPLE 241-[(5-Fluoro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 19% (0.038 g) yield andwas prepared in accordance with the general method of Example 23 using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.12 g,0.63 mmol), 5-fluoro-1H-indole-2-carbaldehyde (0.12 g, 0.76 mmol),NaCNBH₃ (0.040 g, 0.63 mmol, +0.5 equiv.), Et₃N (0.088 mL, 0.63 mmol)and benzoyl isothiocyanate (0.093 mL, 0.69 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.38 (2H, br s), 11.10 (1H, s), 7.41-7.26 (2H,m), 7.25-7.11 (1H, m), 6.96-6.79 (1H, m), 6.37-6.24 (2H, m), 5.83 (2H,s);

¹³C NMR (DMSO-d₆) δ ppm 173.61, 173.81, 158.46, 156.17, 152.94, 136.85,136.10, 132.94, 128.39, 128.30, 114.19, 112.71, 112.61, 109.54, 109.28,104.75, 104.51, 100.82, 100.78, 97.23, 47.35;

MS (ESI) m/z 315 (M+1).

EXAMPLE 251-(1H-Indol-6-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound obtained as a solid in 19% (0.035 g) yield and wasprepared in accordance with the general method of Example 23 using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.12 g,0.63 mmol), 6-formylindole (0.11 g, 0.76 mmol), NaCNBH₃ (0.040 g, 0.63mmol, +0.5 equiv.), Et₃N (0.088 mL, 0.63 mmol) and benzoylisothiocyanate (0.093 mL, 0.69 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.37 (2H, br s), 11.01 (1H, s), 7.53-7.43 (1H,m), 7.33 (1H, s), 7.32-7.25 (2H, m), 7.09-7.03 (1H, m), 6.41-6.34 (1H,m), 6.17 (1H, d, J=2.8 Hz), 5.79 (2H, s);

¹³C NMR (DMSO-d₆) δ ppm 173.76, 152.91, 137.06, 136.21, 128.88, 128.27,127.31, 125.99, 120.35, 118.91, 114.16, 110.24, 101.28, 97.63, 53.32;

MS (ESI) m/z 297 (M+1).

EXAMPLE 261-(1H-Indol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 39% (0.073 g) yield andwas prepared in accordance with the general method of Example 23 using3-amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.12 g,0.63 mmol), 5-formylindole (0.11 g, 0.76 mmol), NaCNBH₃ (0.040 g, 0.63mmol, +0.5 equiv.), Et₃N (0.088 mL, 0.63 mmol) and benzoylisothiocyanate (0.093 mL, 0.69 mmol).

¹H NMR (DMSO-d₆) δ ppm 12.33 (2H, br s), 11.07 (1H, s), 7.52 (1H, s),7.36-7.29 (2H, m), 7.29-7.25 (1H, m), 7.21-7.12 (1H, m), 6.39-6.34 (1H,m), 6.21-6.16 (1H, m), 5.77 (2H, s);

¹³C NMR (DMSO-d₆) δ ppm 173.32, 152.51, 136.63, 135.20, 127.83, 127.50,126.15, 125.81, 120.54, 118.81, 113.82, 111.40, 101.00, 97.28, 52.99;

MS (ESI) m/z 297 (M+1).

EXAMPLE 271-[(5-Fluoro-1H-indol-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

3-Amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.10 g,0.52 mmol) was dissolved in methanol (4 mL) and5-fluoro-1H-indole-3-carboxaldehyde (0.10 g, 0.63 mmol), NaCNBH₃ (0.033g, 0.52 mmol) and Et₃N (0.073 g, 0.52 mmol) were added. The resultingmixture was stirred at r.t. overnight. Additional NaCNBH₃ (0.01 g) wasadded and the mixture was heated at 50° C. for 5 h. The reaction mixturewas cooled to r.t. and concentrated in vacuo. The crude intermediate wasdissolved in CH₂Cl₂ (3 mL) and methanol (1 mL). Benzoyl isothiocyanate(0.078 mL, 0.58 mmol) was added and after stirring at r.t. for 1 h themixture was concentrated in vacuo. The residue was dissolved in ammonia(7N in methanol, 3 mL) and heated at 80° C. for 2 h. The solvent wasremoved in vacuo and after purification by preparative HPLC, the titlecompound (0.035 g, 21%) was obtained as a solid.

¹H NMR (DMSO-d₆) δ ppm 12.29 (2H, s), 11.38-11.08 (1H, m), 7.76-7.68(1H, m), 7.65-7.59 (1H, m), 7.37-7.30 (1H, m), 7.30-7.27 (1H, m),6.96-6.86 (1H, m), 6.37 (1H, d, J=2.8 Hz), 5.84 (2H, s);

¹³C NMR (DMSO-d₆) δ ppm 173.09, 158.27, 155.97, 152.81, 136.59, 133.11,128.14, 128.09, 126.70, 126.59, 114.37, 113.01, 112.91, 109.95, 109.91,109.86, 109.68, 104.70, 104.46, 97.74, 46.10;

MS (ESI) m/z 315 (M+1).

EXAMPLE 281-(1H-Imidazol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

3-Amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.10 g,0.52 mmol) was dissolved in methanol (4 mL) and 4-formylimidazole (0.060g, 0.63 mmol), NaCNBH₃ (0.033 g, 0.52 mmol) and Et₃N (0.073 g, 0.52mmol) were added. The resulting mixture was stirred at r.t. overnight.The solvent was removed in vacuo and the residue was dissolved in CH₂Cl₂(3 mL) and methanol (1 mL). Benzoyl isothiocyanate (0.078 mL, 0.58 mmol)was added and after stirring at r.t. for 30 minutes the mixture wasconcentrated in vacuo. The residue was dissolved in ammonia (7N inmethanol, 3 mL) and heated at 80° C. for 1 h. The precipitated productwas filtered and washed with methanol, followed by diethyl ether. Thecrude product was purified by preparative HPLC, obtaining 0.017 g (13%)of the title compound as a solid. OC 710/07

¹H NMR (DMSO-d₆) δ ppm 12.49-11.78 (3H, m), 7.53 (1H, s), 7.30 (1H, d,J=2.8 Hz), 7.05 (1H, s), 6.36 (1H, d, J=3.0 Hz), 5.54 (2H, s);

MS (ESI) m/z 335 (M+1).

EXAMPLE 291-(1H-Imidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Ethyl 3[(1H-imidazol-2-ylmethyl)amino]-1H-pyrrole-2-carboxylate

A reaction mixture with 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester(0.2 g, 1.30 mmol), 2-imidazolecarboxaldehyde (0.15 g, 1.53 mmol),NaCNBH₃ (0.082 g, 1.30 mmol) and OHAc (0.15 mL, 2.60 mmol) in methanol(5 mL) was stirred at r.t. for 2 h. The solvent was evaporated in vacuoand the residue was dissolved in ethyl acetate. Washed with water andthe aqueous layer was extracted twice with ethyl acetate. The combinedorganic layers were dried (MgSO₄), filtered and concentrated. The crudeproduct was purified by flash column chromatography (CH₂Cl₂/methanolgradient; 0 to 20% methanol), obtaining 0.30 g (99%) of the titlecompound.

¹H NMR (DMSO-d₆) δ ppm 10.84 (1H, br s), 7.03 (2H, s), 6.79-6.64 (1H,m), 5.76 (1H, br s), 5.68-5.57 (1H, m), 4.29 (2H, d, J=5.8 Hz), 4.19(2H, q, J=7.1 Hz), 3.16 (1H, s), 1.26 (3H, t, J=7.1 Hz);

MS (ESI) m/z 235 (M+1).

(b)1-(1H-Imidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Benzoyl isothiocyanate (0.19 mL, 1.41 mmol) was added to a stirredsolution of ethyl3-[(1H-imidazol-2-ylmethyl)amino]-1H-pyrrole-2-carboxylate (0.3 g, 1.28mmol) in CH₂Cl₂ (4 mL) and methanol (2 mL) and the mixture was stirredat r.t. for 1 h. The solvent was evaporated in vacuo and the residue wasdissolved in ammonia (7N in methanol, 7 mL) and heated at 80° C. for 1h. The crude product was filtrated and purified by preparative HPLC,obtaining 0.110 g, (35%) of the title compound as a white solid.

¹H NMR (DMSO-d₆) δ ppm 12.46-12.14 (2H, m), 11.81 (1H, br s), 7.28 (1H,d, J=2.5 Hz), 6.99 (1H, s), 6.79 (1H, s), 6.13 (1H, d, J=2.8 Hz), 5.67(2H, s);

MS (ESI) m/z 248 (M+1).

EXAMPLE 301-[(5-Chloro-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Ethyl3-{[(5-chloro-1H-benzimidazol-2-yl)methyl]amino}-1H-pyrrole-2-carboxylate

A reaction mixture of 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester(0.077 g, 0.5 mmol), NaCNBH₃ (0.057 g, 0.9 mmol) and HOAc (0.030 g, 0.5mmol) in methanol (4 mL) were stirred at r.t. for 5 minutes before5-chloro-1H-benzimidazole-2-carbaldehyde (0.144 g, 0.8 mmol) was added,followed by addition of CH₂Cl₂ (1 mL) and DMF (0.4 mL). The resultingmixture was allowed to stir for 16 h at r.t. under nitrogen atmosphere.Additional 5-chloro-1H-benzimidazole-2-carbaldehyde (0.030 g) andNaCNBH₃ (0.015 g) were added and the reaction mixture was stirred at 4h. The reaction mixture was neutralized with 2M NaOH and diluted withethyl acetate. Extracted with water and the organic layer was dried(Na₂SO₄) and concentrated. The crude product was purified by flashcolumn chromatography (heptane/ethyl acetate gradient; 0 to 100% ethylacetate), obtaining 0.074 g (46%) of the title product.

¹H NMR (CDCl₃) δ ppm 8.28 (1H, br s), 7.52 (1H, s), 7.44 (1H, d, J=2.0Hz), 7.22 (1H, d, J=2.0 Hz), 6.66 (1H, s), 5.61 (1H, t, J=2.4 Hz), 4.67(2H, s), 4.27 (2H, m), 1.33 (3H, t, J=6.8 Hz);

MS (ESI) m/z 319 (M+1).

(b)1-[(5-Chloro-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

A solution of ethyl3-{[(5-chloro-1H-benzimidazol-2-yl)methyl]amino}-1H-pyrrole-2-carboxylate(0.074 g, 0.23 mmol) in CH₂Cl₂ was stirred for 5 minutes. DMF (0.2 mL)was added to enhance solubility. Benzoyl isothiocyanate (0.045 g, 0.28mmol) was added and the mixture was stirred for 1 h then concentrated invacuo. The crude intermediate was taken up in ammonia (7N in methanol, 2mL) and was stirred at 70° C. for 1.5 h in a sealed vessel. Aftercooling to r.t. the precipitated product was collected by vacuumfiltration, washed with diethyl ether and dried, obtaining 0.033 g (43%)of the title product as a white solid.

¹H NMR (DMSO-d₆) δ ppm 12.33 (3H, br s), 7.48 (2H, m), 7.32 (1H, s),7.17 (1H, d, J=8.0 Hz), 6.21 (1H, s), 5.88 (2H, s);

MS (ESI) m/z 332 (M+1).

EXAMPLE 311-[(4,5-Dimethyl-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 4,5-Dimethyl-1H-benzimidazole-2-carbaldehyde

3,4-Dimethylbenzene-1,2-diamine (0.409 g, 3.0 mmol) and dichloroaceticacid (0.768 g, 6.0 mmol) in 4N HCl (10 mL) were heated at 100° C. fortwo days. After cooling to r.t. the mixture was filtrated and the motherliquor was extracted with chloroform (4 times). The pH was set to 12using 2M NaOH and the resulting white precipitate was collected byfiltration. The crude product was used in the next step without furtherpurification.

MS (ESI) m/z 175 (M+1).

(b) Ethyl3-{[(4,5-dimethyl-1H-benzimidazol-2-yl)methyl]amino}-1H-pyrrole-2-carboxylate

3-Amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.077 g, 0.5 mmol),4,5-dimethyl-1H-benzimidazole-2-carbaldehyde (0.130 g, 0.75 mmol) andHOAc (0.045 g, 0.75 mmol) were stirred in methanol (4 mL) followed byaddition of NaCNBH₃. The resulting mixture was stirred at r.t. for 16 h.The reaction mixture was neutralized with 2M NaOH and the solvent wasremoved in vacuo. The residue was dissolved in ethyl acetate andextracted with water. The organic layer was dried (Na₂SO₄) andconcentrated. The crude product was purified by flash columnchromatography (heptane/ethyl acetate gradient; 0 to 100% ethylacetate), obtaining a white solid, 0.043 g (27%) of the title compound,as a tautomeric mixture (1:1).

¹H NMR (DMSO-d₆) δ ppm 12.15 (1H, s), 12.04 (1H, s), 10.81 (2H, s), 7.26(1H, d, J=8.4 Hz), 7.12 (1H, d=8.0 Hz), 6.94 (2H, d, J=8.4 Hz), 6.72(2H, s), 5.93 (2H, s), 5.70 (1H, s), 5.61 (1H, s), 4.44 (4H, dd, J=9.2,6.0 Hz), 4.22 (4H, m), 2.44 (3H, s), 2.37 (3H, s), 2.29 (6H, s), 1.30(6H, m);

MS (ESI) m/z 313 (M+1).

(c)1-[(4,5-Dimethyl-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Ethyl3-{[(4,5-dimethyl-1H-benzimidazol-2-yl)methyl]amino}-1H-pyrrole-2-carboxylate(0.043 g, 0.14 mmol) was dissolved in CH₂Cl₂ (1.5 mL) and benzoylisothiocyanate (0.026 g, 0.16 mmol) was added. After stirring at r.t.for 1 h the solvent was removed in vacuo. The residue was dissolved inammonia (7N in methanol) and heated to 70° C. for 2 h in a sealedvessel. The solvent was removed in vacuo and the residue was purified bypreparative HPLC, obtaining a white solid, 0.008 g (18%) of the titlecompound, as a tautomeric mixture (1:1).

¹H NMR (DMSO-d₆) δ ppm 12.18 (2H, s), 11.98 (2H, s), 7.28 (2H, t, J=2.4Hz), 7.19 (1H, d, J=8.0 Hz), 7.08 (1H, d, J=8.0 Hz), 6.92 (2H, t, J=8.0Hz), 6.14 (2H, dd, J=8.0, 2.8 Hz), 5.89 (2H, s), 5.86 (2H, s), 2.41 (3H,s), 2.37 (3H, s), 2.29 (3H, s), 2.28 (3H, s);

MS (ESI) m/z 326 (M+1).

EXAMPLE 327-Bromo-1-isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) 3-Amino-4-bromo-1H-pyrrole-2-carboxylic acid ethyl ester

3-Amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.92 g, 0.6 mmol) wasdissolved in HOAc (1 mL) and bromine water (0.96 g, 0.6 mmol) was added.The mixture was stirred for 1 h at r.t., and the resulted whiteprecipitate was collected by filtration and washed with diethyl ether.The title compound (0.136 g, 97%) was obtained as a white solid and usedin the next step without further purification.

¹H NMR (DMSO-d₆) δ ppm 11.67 (1H, s), 7.05 (1H, s), 6.02 (2H, br s),4.25 (2H, q, J=7.2 Hz), 1.28 (3H, t, J=7.2 Hz);

MS (ESI) m/z 233 (M+1).

(b) 4-Bromo-3-(isobutylamino)-1H-pyrrole-2-carboxylic acid ethyl ester

3-Amino-4-bromo-1H-pyrrole-2-carboxylic acid ethyl ester (0.136 g, 0.58mmol) and isobutyraldehyde (0.067 g, 0.93 mmol) were stirred inCH₂Cl₂/MeOH (1:1, 3 mL) at r.t. for 2 h. NaCNBH₃ (0.065 g, 1.04 mmol)and HOAc (0.035 g, 0.58 mmol) were added and the mixture was stirred atr.t. for 2 h and then stirred at 50° C. for 16 h. Additionalisobutyraldehyde (1 equiv.) and NaCNBH₃ (0.5 equiv.) were added and themixture was continued stirring at 50° C. overnight. The reaction mixturewas neutralized with 2 M NaOH solution and the solvents were removed invacuo. The residue was taken up in ethyl acetate and extracted withwater. The organic layer was dried (Na₂SO₄) and concentrated. The crudeproduct was purified by flash chromatography (heptane/ethyl acetategradient, 0 to 30% ethyl acetate), obtaining the title compound (0.040g, 24%) as a white solid.

¹H NMR (CDCl₃) δ ppm 6.75 (1H, s), 4.32 (2H, q, J=7.2 Hz), 3.28 (2H, d,J=6.8 Hz), 1.85 (1H, m), 1.35 (3H, t, J=7.2 Hz), 0.97 (3H, d, J=6.8 Hz);

MS (ESI) m/z 289 (M+1).

(c)7-Bromo-1-isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Benzoyl isothiocyanate (0.034 g, 0.2 mmol) was added to a solution of4-bromo-3-(isobutylamino)-1H-pyrrole-2-carboxylic acid ethyl ester(0.050 g, 0.17 mmol) in CH₂Cl₂ and the resulting mixture was stirred atr.t. for 1 h before it was concentrated in vacuo. The residue wasdissolved in ammonia (7M in methanol, 1.5 mL) and stirred at 70° C. for4 h. Additional ammonia (7M in methanol, 1 mL) was added and the mixturewas stirred at 80° C. for 5 h. The mixture was cooled to r.t. and theprecipitated product was filtered and washed with diethyl ether. Afterrecrystallization with methanol the title compound (0.028 g, 55%) wasobtained as a white solid.

¹H NMR (DMSO-d₆) δ ppm 12.57 (2H, br s), 7.58 (1H, s), 4.92 (1H, br s),4.42 (1H, br s), 2.39 (1H, m), 0.94 (6H, d, J=6.4 Hz);

MS (ESI) m/z 303 (M+1).

EXAMPLE 331-(3-Chlorophenyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one(a) Ethyl 3[(3-chlorophenyl)amino]-1H-pyrrole-2-carboxylate

A mixture of 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester (0.20 g,1.3 mmol), 3-bromochlorobenzene (0.30 g, 1.6 mmol), Pd₂(dba)₃ (0.048 g,0.052 mmol), rac-BINAP (0.048 g, 0.078 mmol) and cesium carbonate (0.59g, 1.8 mmol) was heated at 100° C. in a sealed microwave vial undernitrogen atmosphere overnight. Additional Pd₂(dba)₃ (0.10 g, 0.11 mmol)and R,S-BINAP (0.11 g, 0.18 mmol) were added and the reaction wascontinued stirring at 100° C. overnight. Additional 3-bromochlorobenzene(0.15 g), Pd₂(dba)₃ (0.098 g) and R,S-BINAP (0.098 g) were added and thereaction was continued stirring at 100° C. for three more days. Thereaction mixture was poured into ethanol and the resulting solution wasfiltered. The filtrate was evaporated in vacuo and the residue waspurified by flash column chromatography (heptane/ethyl acetate gradient;0 to 30% ethyl acetate), obtaining 0.052 g (15%) of the title compound.

¹H NMR (CDCl₃) δ ppm 8.42 (1H, br s), 7.17 (1H, t, J=8.0 Hz), 7.14 (1H,t, J=2.0 Hz), 6.96-6.94 (1H, m), 6.87-6.84 (1H, m), 6.82 (1H, t, J=3.0Hz), 6.32 (1H, t, J=3.0 Hz), 4.35 (2H, q, J=7.2 Hz), 1.38 (3H, t, J=7.1Hz);

MS (ESI) m/z 263 (M−1).

(b)1-(3-Chlorophenyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one

Benzoyl isothiocyanate (0.035 g, 0.22 mmol) in CH₂Cl₂ (0.5 mL) was addedto ethyl 3-[(3-chlorophenyl)amino]-1H-pyrrole-2-carboxylate (0.052 g,0.20 mmol) in CH₂Cl₂ (0.5 mL). The mixture was stirred at r.t.overnight. Additional benzoyl isothiocyanate (0.035 g+0.035 g+0.035 g)were added over 6 h and the reaction was continued stirring at 50° C.for 3 days. The solvent was removed in vacuo and the residue wasdissolved in ammonia (7N in methanol, 4 mL). The reaction was heated at50° C. for 2 h. The crude product was purified by preparativechromatography, obtaining 0.009 g (15%) of the title compound as asolid.

¹H NMR (DMSO-d₆) δ ppm 12.41 (2H, br s), 7.60-7.57 (3H, m), 7.41-7.37(1H, m), 7.25 (1H, d, J=2.8 Hz), 5.36 (1H, d, J=2.8 Hz);

¹³C NMR (DMSO-d₆) δ ppm 173.8, 152.8, 141.5, 137.9, 133.5, 131.3, 129.0,128.6, 127.7, 127.3, 113.3, 96.7;

MS (ESI) m/z 278 (M+1).

Screens

Methods for the determination of MPO inhibitory activity are disclosedin patent application WO 02/090575. The pharmacological activity ofcompounds according to the invention was tested in the following screenin which the compounds were either tested alone or in the presence ofadded tyrosine:

Assay buffer: 20 mM sodium/potassium phosphate buffer pH 6.5 containing10 mM taurine and 100 mM NaCl.

Developing reagent: 2 mM 3,3′,5,5′-tetramethylbenzidine (TMB), 200 μMKI, 200 mM acetate buffer pH 5.4 with 20% DMF.

To 10 μl of diluted compounds in assay buffer, 40 μl of human MPO (finalconcentration 2.5 nM), with or without 20 μM tyrosine (finalconcentration, if present, 8 μM), was added and the mixture wasincubated for 10 minutes at ambient temperature. Then 50 μl of H₂O₂(final concentration 100 μM), or assay buffer alone as a control, wereadded. After incubation for 10 minutes at ambient temperature, thereaction was stopped by adding 10 μl 0.2 mg/ml of catalase (finalconcentration 18 μg/ml). The reaction mixture was left for an additional5 minutes before 100 μl of TMB developing reagent was added. The amountof oxidised 3,3′,5,5′-tetramethylbenzidine formed was then measuredafter about 5 minutes using absorbance spectroscopy at about 650 nM.IC₅₀ values were then determined using standard procedures.

When tested in at least one version of the above screen, the compoundsof Examples 1 to 32 gave IC₅₀ values of less than 60 μM, indicating thatthey are expected to show useful therapeutic activity. Representativeresults are shown in the following Table.

Inhibition of MPO (in the presence of tyrosine) Compound IC50 μM Example2 0.26 Example 5 0.22 Example 11 1.1

1-29. (canceled)
 30. A method of treating or reducing the risk of Parkinson's disease, which comprises administering to a person suffering from or at risk of said disease a therapeutically effective amount of a compound of formula (I),

a tautomer thereof, or a pharmaceutically acceptable salt of any of the foregoing, wherein: at least one of X and Y is S, and the other is O or S; L is C₁ to C₇ alkylene, said alkylene optionally incorporating a group selected from O, S(O)_(n) and NR⁶, and optionally incorporating one or two carbon-carbon double bonds, wherein said alkylene is optionally substituted by one or more substituents selected independently from OH, halogen, CN, NR⁴R⁵, C₁ to C₆ alkyl and C₁ to C₆ alkoxy, said alkoxy optionally incorporating a carbonyl adjacent to the oxygen; n is 0, 1 or 2; R¹ is hydrogen; or R¹ is a saturated or partially unsaturated 3- to 7-membered ring optionally incorporating a carbonyl group and optionally incorporating one or two heteroatoms selected independently from O, N and S, wherein said ring is optionally substituted by one or more substituents independently selected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH, C₁ to C₇ alkyl, C₁ to C₇ alkoxy, CN, CONR²R³, NR²COR³ and COR³, wherein said C₁ to C₇ alkoxy is optionally substituted by C₁ to C₆ alkoxy and wherein said C₁ to C₆ alkoxy optionally incorporates a carbonyl adjacent to the oxygen, and wherein said C₁ to C₇ alkyl optionally incorporates a carbonyl at any position in the alkyl and is optionally substituted by hydroxy and C₁ to C₆ alkoxy, wherein the C₁ to C₆ alkoxy optionally incorporates a carbonyl adjacent to the oxygen; or R¹ is an aromatic ring system selected from phenyl, biphenyl, naphthyl and a monocyclic or bicyclic heteroaromatic ring structure containing 1 to 3 heteroatoms independently selected from O, N and S, wherein said aromatic ring system is optionally substituted by one or more substituents independently selected from halogen, SO₂R⁹, SO₂NR⁹R¹⁰, OH, C₁ to C₇ alkyl, C₁ to C₇ alkoxy, CN, CONR²R³, NR²COR³ and COR³; wherein said C₁ to C₇ alkoxy is optionally substituted by C₁ to C₆ alkoxy and wherein said C₁ to C₆ alkoxy optionally incorporates a carbonyl adjacent to the oxygen and wherein said C₁ to C₇ alkyl optionally incorporates a carbonyl at any position in the alkyl and is optionally substituted by hydroxy or a C₁ to C₆ alkoxy, wherein the C₁ to C₆ alkoxy optionally incorporates a carbonyl adjacent to the oxygen; at each occurrence, R², R³, R⁴, R⁵, R⁶, R⁹ and R¹⁰ independently are hydrogen, C₁ to C₆ alkyl and C₁ to C₆ alkoxy, wherein said C₁ to C₆ alkoxy optionally incorporates a carbonyl adjacent to the oxygen, and said C₁ to C₆ alkyl is optionally substituted by one or more halogen, C₁ to C₆ alkoxy, CHO, C₂ to C₆ alkanoyl, OH, CONR⁷R⁸ and NR⁷COR⁸; the groups NR²R³, NR⁴R⁵ and NR⁹R¹⁰ independently represent a 5- to 7-membered saturated azacyclic ring optionally incorporating one additional group selected from O, S and NR¹¹, said 5- to 7-membered saturated azacyclic ring optionally substituted by halogen, C₁ to C₆ alkoxy, CHO, C₂ to C₆ alkanoyl, OH, CONR⁷R⁸ and NR⁷COR⁸; at each occurrence R⁷, R⁸ and R¹¹ independently represent hydrogen or C₁ to C₆ alkyl, or the group NR⁷R⁸ represents a 5- to 7-membered saturated azacyclic ring optionally incorporating one additional group selected from O, S and NR¹¹.
 31. The method according to claim 30, wherein R¹ is hydrogen.
 32. The method according to claim 30, wherein X is S and Y is O.
 33. The method according to claim 30, wherein X is O and Y is S.
 34. The method according to claim 30, wherein L is C₁ to C₇ alkylene; said alkylene being optionally substituted by one or more C₁ to C₆ alkoxy.
 35. The method according to claim 30, wherein L is C₁ to C₃ alkylene, and said alkylene is optionally substituted by one or more C₁ to C₆ alkoxy.
 36. The method according to claim 30, wherein R¹ is a saturated or partially unsaturated 3- to 7-membered ring optionally incorporating a carbonyl group and optionally incorporating one or two heteroatoms selected independently from O, N and S, said ring being optionally substituted by one or more substituents independently selected from halogen, C₁ to C₆ alkyl and C₁ to C₆ alkoxy, said C₁ to C₆ alkoxy optionally substituted by C₁ to C₆ alkoxy.
 37. The method according to claim 30, wherein R¹ is an aromatic ring system selected from phenyl, biphenyl, naphthyl; and a five- or six-membered heteroaromatic ring containing 1 to 3 heteroatoms independently selected from O, N and S; wherein said aromatic ring system is optionally substituted by one or more substituents independently selected from halogen, C₁ to C₆ alkyl, and C₁ to C₆ alkoxy, said C₁ to C₆ alkoxy optionally substituted by C₁ to C₆ alkoxy.
 38. The method according to claim 30, wherein L is an optionally substituted C₁ to C₃ alkylene, and R¹ is a saturated or partially unsaturated 3- to 7-membered ring optionally incorporating a carbonyl group and optionally incorporating one or two heteroatoms selected independently from O, N and S, wherein said ring is optionally substituted by one or more substituents independently selected from halogen, C₁ to C₆ alkyl and C₁ to C₆ alkoxy, said C₁ to C₆ alkoxy optionally substituted by C₁ to C₆ alkoxy.
 39. The method according to claim 30, wherein L is an optionally substituted C₁ to C₃ alkylene and R¹ is an aromatic ring system selected from phenyl, biphenyl, naphthyl; and a five- or six-membered heteroaromatic ring containing 1 to 3 heteroatoms independently selected from O, N and S, wherein said aromatic ring system is optionally substituted by one or more substituents independently selected from halogen, C₁ to C₆ alkyl and C₁ to C₆ alkoxy, said C₁ to C₆ alkoxy being optionally substituted by C₁ to C₆ alkoxy.
 40. The method according to claim 30, wherein X is S; Y is O; L is an optionally substituted C₁ to C₃ alkylene; and R¹ is optionally substituted phenyl.
 41. The method according to claim 30, wherein X is S; Y is O; L is optionally substituted C₁ to C₃ alkylene; and R¹ is optionally substituted pyridyl.
 42. The method according to claim 30, wherein X is S; Y is O; L is C₁ to C₃ alkylene, substituted with C₁ to C₆ alkoxy; and R¹ is hydrogen.
 43. The method according to claim 30, wherein said compound is selected from the group consisting of: 1-butyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-isobutyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(2-fluoro-benzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[2-(2-methoxyethoxy)-3-propoxybenzyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(6-ethoxy-pyridin-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-piperidin-3-ylmethyl-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-butyl-4-thioxo-1,3,4,5-tetrahydro-2H-pyrrolo[3,2-d]pyrimidin-2-one; 1-(2-isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(2-methoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(2-ethoxy-2-methylpropyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(piperidin-4-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[(1-methylpiperidin-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[2-hydroxy-2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(2-methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(3-methoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(2,4-dimethoxybenzyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[(3-chloropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-{[3-(2-ethoxyethoxy)pyridin-2-yl]methyl}-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[(6-oxo-1,6-dihydropyridin-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(1H-indol-3-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(1H-benzimidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[(5-chloro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-[(5-fluoro-1H-indol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(1H-indol-6-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-c]pyrimidin-4-one; 1-(1H-indol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-c]pyrimidin-4-one; 1-[(5-fluoro-1H-indol-3-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; 1-(1H-imidazol-5-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-c]pyrimidin-4-one; 1-(1H-imidazol-2-ylmethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-c]pyrimidin-4-one; 1-[(5-chloro-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; and 1-[(4,5-dimethyl-1H-benzimidazol-2-yl)methyl]-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one; or a tautomer thereof, or a pharmaceutically acceptable salt of any of the foregoing.
 44. The method according to claim 30, wherein said compound is 1-(2-isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one,

or a tautomer thereof, or a pharmaceutically acceptable salt of any of the foregoing.
 45. A method of treating or reducing the risk of Parkinson's disease, which comprises administering to a person suffering from or at risk of said disease a therapeutically effective amount of 1-(2-isopropoxyethyl)-2-thioxo-1,2,3,5-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one,

or a tautomer thereof, or a pharmaceutically acceptable salt of any of the foregoing. 